Introduction to Chemistry 5th Edition by Rich Bauer - Test Bank

Introduction to Chemistry 5th Edition by Rich Bauer – Test Bank

 

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Sample Questions Are Posted Below

 

Introduction to Chemistry, 5e (Bauer)

Chapter 6   Quantities in Chemical Reactions

 

1) When one molecule of propane, C3H8, burns in a gas grill, it combines with five oxygen molecules to form three CO2 molecules and four H2O molecules. Select the statement below that is incorrect in regard to this reaction.

1. A) The balanced equation for the reaction is C3H8+ 5O2→ 3CO2 + 4H2
2. B) If 5 propane molecules react, 15 CO2molecules should form.
3. C) If 5 propane molecules react, 25 O2molecules must also react.
4. D) If 15 O2molecules react, 9 H2O molecules should form.
5. E) If 12 CO2molecules are formed, then 4 propane molecules must have reacted.

 

Answer:  D

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

2) When ethanol, C2H5OH, a component in some gasoline mixtures, is burned in air, one molecule of ethanol combines with three oxygen molecules to form two CO2 molecules and three H2O molecules. Select the statement below that is incorrect in regard to this reaction.

1. A) The balanced equation for the reaction is C2H5OH + 3O2→ 2CO2+ 3H2
2. B) If 4 ethanol molecules react, 8 CO2molecules should form.
3. C) If 12 H2O molecules are formed, then 9 O2molecules must have reacted.
4. D) If 15 ethanol molecules react, then 45 oxygen molecules must also react.
5. E) If 12 CO2molecules are formed, then 18 H2O molecules should also form.

 

Answer:  C

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

3) When acetylene, C2H2, a fuel used in welding, is burned in air, two molecules of acetylene combine with five oxygen molecules to form four CO2 molecules and two H2O molecules. Select the statement below that is incorrect in regard to this reaction.

1. A) The balanced equation for the reaction is 2C2H2+ 5O2→ 4CO2 + 2H2
2. B) If 8 acetylene molecules react, 12 CO2molecules should form.
3. C) If 12 H2O molecules are formed, then 30 O2molecules must have reacted.
4. D) If 12 CO2molecules are formed, then 6 H2O molecules should also form.
5. E) If 24 ethanol molecules react, then 60 oxygen molecules must also react

 

Answer:  B

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

4) All of the following may change during a chemical reaction except

1. A) the total number of atoms in the system.
2. B) the temperature of the system.
3. C) the color of the system.
4. D) the total number of molecules in the system.
5. E) the physical state of the system.

 

Answer:  A

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

5) When sodium sulfate, Na2SO4, dissolves in water, the ions that are formed for each formula unit that dissolves are:

1. A) Na22+(aq) + SO42−(aq)
2. B) 2Na2+(aq) + SO42−(aq)
3. C) 2Na+(aq) + SO42−(aq)
4. D) Na22+(aq) + S(s) + O42−(aq)
5. E) Na22+(aq) + S2−(aq) + 4O2−(aq)

 

Answer:  C

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions; Aqueous Solutions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Writing and Balancing Chemical Equations; Ions in Water (Electrolytes)

Accessibility:  Keyboard Navigation

 

6) When potassium carbonate, K2CO3, dissolves in water, the ions that are formed for each formula unit that dissolves are:

1. A) K22+(aq) + CO32−(aq)
2. B) 2K2+(aq) + CO32−(aq)
3. C) 2K+(aq) + CO32−(aq)
4. D) 2K+(aq) + C(s) + O32−(aq)
5. E) K22+(aq) + C4+(aq) + 3O2−(aq)

 

Answer:  C

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions; Aqueous Solutions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Writing and Balancing Chemical Equations; Ions in Water (Electrolytes)

Accessibility:  Keyboard Navigation

 

7) When ammonium carbonate, (NH4)2CO3, dissolves in water, the ions that are formed for each formula unit that dissolves are:

1. A) (NH4)22+(aq) + CO32−(aq)
2. B) 2NH4+(aq) + CO32−(aq)
3. C) 2N3−(aq) + 4H+(aq) + CO32−(aq)
4. D) 2N3−(aq) + 4H+(aq) + C(s) + O32−(aq)
5. E) 2N3−(aq) + 4H+(aq) + C4+(aq)+ 3O2−(aq)

 

Answer:  B

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions; Aqueous Solutions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Writing and Balancing Chemical Equations; Ions in Water (Electrolytes)

Accessibility:  Keyboard Navigation

 

8) Which of the following is the best (simplest) balanced equation to represent the chemical reaction shown in the figure on any scale?

 

1. A) 4A + 8B → 12AB
2. B) 2A2+ 4B2→ 4A2B
3. C) 2A2+ 4B2→ 4AB2
4. D) A2+ B2→ AB2
5. E) A2+ 2B2→ 2AB2

 

Answer:  E

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

9) Which of the following is the best (simplest) balanced equation to represent the chemical reaction shown in the figure on any scale?

 

1. A) 16H + 10O → 16H + 10O
2. B) 16H + 10O → 8H2O + O2
3. C) 8H2+ 5O2→ 8H2O + O2
4. D) 2H2+ O2→ 2H2O
5. E) 4H2+ 2O2→ 4H2O

 

Answer:  D

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

10) Which of the following is the best (simplest) balanced equation to represent the chemical reaction shown in the figure on any scale?

 

1. A) 12N + 12H → 12NH
2. B) 6N2+ 6H2→ 4NH3
3. C) 6N2+ 6H2→ 4NH3 + 4N2
4. D) 12N + 12H → 4NH3+ 8N
5. E) N2+ 3H2→ 2NH3

 

Answer:  E

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

11) When the mixture of molecules shown in the molecular-level image undergoes complete reaction, all of these molecules are converted to products. Which of the following reactions could this represent?

 

1. A) N2+ O2→ 2NO
2. B) N2+ 2Cl2→ N2Cl4
3. C) N2+ 2O2→ 2NO2
4. D) N2+ 3H2→ 2NH3
5. E) N2+ 3O2→ 2NO3

 

Answer:  A

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

12) When the mixture of molecules shown in the molecular-level image undergoes complete reaction, all of these molecules are converted to products. Which of the following reactions could this represent?

 

1. A) 2N2+ 3O2→ 2N2O3
2. B) N2+ 2Cl2→ N2Cl4
3. C) O2+ 2H2→ 2H2O
4. D) N2+ 3Cl2→ 2NCl3
5. E) 3N2+ 2H2→ 3N2H4

 

Answer:  D

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

13) When mixed, solutions of aluminum nitrate, Al(NO3)3, and ammonium carbonate, (NH4)2CO3, will form a precipitate of aluminum carbonate, Al2(CO3)3. The balanced equation is 2Al(NO3)3(aq) + 3(NH4)2CO3(aq) → Al2(CO3)3 (s) + 6NH4NO3(aq) Which of the following statements regarding this reaction is incorrect?

3. A) 2 moles of Al(NO3)3will react with 3 moles of (NH4)2CO3.
4. B) If 6 moles of (NH4)2CO3react with sufficient Al(NO3)3, 2 moles of Al2(CO3)3should form.
5. C) If 0.5 mole of (NH4)2CO3react with sufficient Al(NO3)3, 3 moles of Al2(CO3)3should form.
6. D) If 1.5 moles of Al2(CO3)3are formed, given sufficient starting materials, then 9 moles of NH4NO3should also form.
7. E) 4 moles of Al(NO3)3will react with 6 moles of (NH4)2CO3.

 

Answer:  C

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

14) When mixed, solutions of silver nitrate, AgNO3, and sodium phosphate, Na3PO4, will form a precipitate of silver phosphate, Ag3PO4. The balanced equation is 3AgNO3(aq) + Na3PO4(aq) → Ag3PO4(s) + 3NaNO3(aq) Which of the following statements regarding this reaction is incorrect?

4. A) 6 moles of AgNO3will react with 2 moles of Na3PO4.
5. B) 9 moles of AgNO3should react to form 2 moles of Ag3PO4, given sufficient Na3PO4.
6. C) 1.5 moles of NaNO3should form when 0.5 mole of Na3PO4reacts with sufficient AgNO3.
7. D) 3 moles of Ag3PO4should form when 3 moles of Na3PO4react with sufficient AgNO3.
8. E) 2 moles of Na3PO4will react with 6 moles of AgNO3.

 

Answer:  A

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

15) When mixed, solutions of copper(II) nitrate, Cu(NO3)2, and sodium phosphate, Na3PO4, will form a precipitate of copper phosphate, Cu3(PO4)2. The balanced equation is 3Cu(NO3)2(aq) + 2Na3PO4(aq) → Cu3(PO4)2(s) + 6NaNO3(aq) Which of the following statements regarding this reaction is incorrect?

2. A) 8 moles of Na3PO4will react with 12 moles of Cu(NO3)2.
3. B) 1 mole of NaNO3should form when 0.5 mole of Cu(NO3)2reacts with sufficient Na3PO4.
4. C) 12 moles of Cu3(PO4)2should form when 36 moles of Cu(NO3)2reacts with sufficient Na3PO4.
5. D) If 10 moles of Na3PO4react with sufficient Cu(NO3)2, 4 moles of Cu3(PO4)2should form.
6. E) If 5 moles of Cu3(PO4)2are needed, it would require the combination of 15 moles of Cu(NO3)2and 10 moles of Na3PO4.

 

Answer:  D

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

16) Consider the reaction between hydrogen and oxygen gases to form water: 2H2(g) + O2(g) → 2H2O(l) Which of the following is not conserved in this reaction?

1. A) atoms
2. B) moles of atoms
3. C) moles of molecules
4. D) mass

 

Answer:  C

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Writing and Balancing Chemical Equations; Calculating Amounts of Reactant; Product (including solutions)

Accessibility:  Keyboard Navigation

 

17) Consider the reaction between sodium metal and chlorine gas to form sodium chloride: 2Na(s) + Cl2(g) → 2NaCl(s) Which of the following is not conserved in this reaction?

1. A) atoms
2. B) moles of atoms
3. C) moles of molecules
4. D) mass

 

Answer:  C

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

18) Consider the reaction between acetylene, C2H2, and oxygen in a welding torch: 2C2H2(g) + 5O2(g) → 4CO2(g) + 2H2O(g) Which of the following is not conserved in this reaction?

1. A) atoms
2. B) moles of atoms
3. C) moles of molecules
4. D) mass

 

Answer:  C

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

19) Which of the following equations is balanced?

1. A) P4(s) + 10O2(g) → P4O10(s)
2. B) ZnS(s) + 3O2(g) → ZnO(s) + 2SO2(g)
3. C) NH3(g) + O2(g) → NO2(g) + H2O(g)
4. D) 4KBrO3(s) → 3KBrO4(s) + KBr(s)
5. E) 2Na(s) + P(s) → Na3P(s)

 

Answer:  D

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

20) Phosphine, PH3, a reactive and poisonous compound, reacts with oxygen as follows: 4PH3(g) + 8O2(g) → P4O10(s) + 6H2O(g) If 9.2 moles of phosphine react with sufficient oxygen, how many moles of P4O10 should form?

4. A) 4.0 moles
5. B) 9.2 moles
6. C) 37 moles
7. D) 2.3 moles
8. E) 6.0 moles

 

Answer:  D

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

21) Phosphine, PH3, a reactive and poisonous compound, reacts with oxygen as follows: 4PH3(g) + 8O2(g) → P4O10(s) + 6H2O(g) If you need to make 6.5 moles of P4O10, how many moles of PH3 is required for the reaction?

6. A) 6.5 moles
7. B) 13 moles
8. C) 26 moles
9. D) 3.2 moles
10. E) 1.6 moles

 

Answer:  C

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

22) Given that 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g), if 6.3 moles of NH3 react with sufficient oxygen, how many moles of NO should form?

4. A) 4.0 moles
5. B) 6.3 moles
6. C) 6.0 moles
7. D) 5.0 moles
8. E) 3.2 moles

 

Answer:  B

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

23) Given that 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g), if 8.2 moles of NH3 react with sufficient oxygen, how many moles of water should form?

6. A) 6.0 moles
7. B) 4.0 moles
8. C) 5.0 moles
9. D) 12 moles
10. E) 8.2 moles

 

Answer:  D

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant; Product (including solutions)

Accessibility:  Keyboard Navigation

 

24) Given that 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g), if 4.5 moles of NH3 react with sufficient oxygen, how many moles of H2O should form?

4. A) 4.0
5. B) 4.5
6. C) 6.0
7. D) 6.8
8. E) 5.5

 

Answer:  D

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

25) Consider the reaction between sodium metal and chlorine gas to form sodium chloride (table salt): 2Na(s) + Cl2(g) → 2NaCl(s) If 3.6 moles of chlorine react with sufficient sodium, how many grams of sodium chloride should form?

1. A) 1.1 x 102g
2. B) 2.1 x 102g
3. C) 4.2 x 102g
4. D) 0.13 g
5. E) 0.062 g

 

Answer:  C

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

26) Consider the reaction between acetylene, C2H2, and oxygen in a welding torch: 2C2H2(g) + 5O2(g) → 4CO2(g) + 2H2O(g) If 5.4 moles of acetylene react with sufficient oxygen, how many grams of CO2 should form?

2. A) 2.4 x 102g
3. B) 9.5 x 102g
4. C) 4.8 x 102g
5. D) 1.5 x 102g
6. E) 0.49 g

 

Answer:  C

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

27) Consider the reaction between hydrogen and oxygen gases to form water: 2H2(g) + O2(g) → 2H2O(l) If 8.5 moles of oxygen react with sufficient hydrogen, how many grams of water should form?

1. A) 0.94 g
2. B) 0.47 g
3. C) .76 g
4. D) 3.1 x 102g
5. E) 1.5 x 102g

 

Answer:  D

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

28) Phosphine, PH3, a reactive and poisonous compound, reacts with oxygen as follows: 4PH3(g) + 8O2(g) → P4O10(s) + 6H2O(g) If 15.0 g of phosphine reacts with sufficient oxygen, how many grams of P4O10 will be formed?

1. A) 125 g
2. B) 31.3 g
3. C) 5.00 x 102g
4. D) 18.9 g
5. E) 75.7 g

 

Answer:  B

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

29) Given the balanced equation 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g), if 82.0 g of NH3 react with sufficient oxygen, how many grams of NO should form?

1. A) 145 g
2. B) 5.80 x 102g
3. C) 46.5 g
4. D) 186 g
5. E) 11.6 g

 

Answer:  A

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

30) Consider the reaction between sodium metal and chlorine gas to form sodium chloride (table salt): 2Na(s) + Cl2(g) → 2NaCl(s) If 12.5 g of sodium react with sufficient chlorine, how many grams of sodium chloride should form?

15. A) 15.9 g
16. B) 31.8 g
17. C) 63.6 g
18. D) 4.92 g
19. E) 9.84 g

 

Answer:  B

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

31) Given the balanced equation 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g), if 32.5 g of NH3 react with sufficient oxygen, how many grams of H2O should form?

51. A) 51.6 g
52. B) 8.60 g
53. C) 34.4 g
54. D) 206.4 g
55. E) 878 g

 

Answer:  A

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

32) When copper reacts with sulfur at high temperature, copper(I) sulfide is formed. 2Cu(s) + S(s) → Cu2S(s) If the mass of the Cu2S formed is 1.17 g, what mass of copper should have reacted?

1. A) 0.934 g
2. B) not enough information
3. C) 0.78 g
4. D) 2.34 g
5. E) 0.467 g

 

Answer:  A

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

33) When magnesium is heated in air, it reacts with oxygen to form magnesium oxide: 2Mg(s) + O2(g) → 2MgO(s) If the mass of the magnesium solid increases by 0.335 g, what mass of magnesium metal should have reacted?

1. A) 0.882 g
2. B) 0.441 g
3. C) 0.509 g
4. D) 1.02 g
5. E) not enough information

 

Answer:  C

Difficulty: 3 Hard

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

34) Consider the reaction between sodium metal and chlorine gas to form sodium chloride (table salt): 2Na(s) + Cl2(g) → 2NaCl(s) If the mass of the sodium solid increases by 0.500 g, what mass of sodium metal should have reacted?

1. A) 0.250 g
2. B) 0.500 g
3. C) 0.0811 g
4. D) 0.162 g
5. E) 0.324 g

 

Answer:  E

Difficulty: 3 Hard

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

35) When a 0.525 g piece of zinc is placed in a solution of copper(II) sulfate, copper metal and zinc sulfate are formed. Balance the equation for the reaction, and determine the mass of copper(II) sulfate that would react with this quantity of zinc. ___ Zn(s) + ___CuSO4(aq) → ___ZnSO4(aq) + ___Cu(s)  (unbalanced)

65. A) 65.4 g
66. B) 0.641 g
67. C) 1.28 g
68. D) 2.56 g
69. E) 159 g

 

Answer:  C

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

36) Small amounts of oxygen gas can be produced for laboratory use by heating potassium chlorate, which causes it to decompose by the following reaction: ___KClO3(s) → ____KCl(s) + ___O2(g) (unbalanced) Balance the equation, and determine the mass of oxygen that should be formed if 10.0 g of potassium chlorate decomposes.

7. A) 7.83 g
8. B) 115 g
9. C) 3.92 g
10. D) 38.3 g
11. E) 57.4 g

 

Answer:  C

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

37) Small amounts of oxygen gas can be produced for laboratory use by heating potassium chlorate, which causes it to decompose by the following reaction: ___KClO3(s) → ____KCl(s) + ___O2(g) (unbalanced) Balance the equation, and determine the mass of oxygen that should be formed if 15.0 g of potassium chlorate decomposes.

11. A) 11.7 g
12. B) 57.5 g
13. C) 173 g
14. D) 5.88 g
15. E) 86.1 g

 

Answer:  D

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

38) When mercury(II) oxide, a red crystalline solid, is heated, it decomposes to form liquid mercury and oxygen gas, according to the following equation: ___HgO(s) → ___Hg(l) + ___O2(g) (unbalanced) Balance the equation and determine the mass of mercury that should be formed when 12.3 g of HgO is heated.

22. A) 22.8 g
23. B) 11.4 g
24. C) 5.70 g
25. D) 13.3 g
26. E) 6.64 g

 

Answer:  B

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

39) When mercury(II) oxide, a red crystalline solid, is heated, it decomposes to form liquid mercury and oxygen gas, according to the following equation: ___HgO(s) → ___Hg(l) + ___O2(g) (unbalanced) Balance the equation and determine the mass of mercury that should be formed when 15.6 g of HgO is heated.

28. A) 28.9 g
29. B) 7.22 g
30. C) 14.4 g
31. D) 16.9 g
32. E) 13.2 g

 

Answer:  C

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

40) When phosphorus reacts with chlorine, phosphorus trichloride is formed according to the equation: ___P4(s) + ___Cl2(g) → ___PCl3(l) (unbalanced) Balance the equation and determine how many grams of chlorine would be required to react with 10.6 g of phosphorus.

6. A) 6.07 g
7. B) 24.3 g
8. C) 36.4 g
9. D) 18.5 g
10. E) 74.1 g

 

Answer:  C

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

41) When phosphorus reacts with chlorine, phosphorus trichloride is formed according to the following equation: ___P4(s) + ___Cl2(g) → ___PCl3(l) (unbalanced) Balance the equation and determine how many grams of chlorine would be required to react with 21.2 g of phosphorus.

12. A) 12.1 g
13. B) 48.6 g
14. C) 37.0 g
15. D) 148 g
16. E) 72.8 g

 

Answer:  E

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

42) Nitrogen and hydrogen react together to form ammonia according to the equation: ___N2(g) + ___H2(g) → ___NH3(g) (unbalanced) Balance the equation, and determine how many grams of hydrogen would be required to react with 25.2 g of nitrogen.

1. A) 1.82 g
2. B) 3.64 g
3. C) 5.45 g
4. D) 1.34 g
5. E) 0.891

 

Answer:  C

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

43) Nitrogen and hydrogen react together to form ammonia according to the equation: ___N2(g) + ___H2(g) → ___NH3(g) (unbalanced) Balance the equation, and determine how many grams of hydrogen would be required to react with 50.4 g of nitrogen.

10. A) 10.9 g
11. B) 3.64 g
12. C) 7.28 g
13. D) 2.68 g
14. E) 1.78 g

 

Answer:  A

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

44) When phosphorus reacts with chlorine, phosphorus trichloride is formed according to the equation: ___P4(s) + ___Cl2(g) → ___PCl3(l) (unbalanced) Balance the equation and determine how many grams of phosphorus reactant would be required to produce 25.0 g of phosphorus trichloride, assuming there is sufficient chlorine available.

22. A) 22.6 g
23. B) 45.1 g
24. C) 5.64 g
25. D) 111 g
26. E) 90.2 g

 

Answer:  C

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

45) When phosphorus reacts with chlorine, phosphorus trichloride is formed according to the following equation: ___P4(s) + ___Cl2(g) → ___PCl3(l) (unbalanced) Balance the equation and determine how many grams of phosphorus reactant would be required to produce 75.0 g of phosphorus trichloride, assuming there is sufficient chlorine available.

67. A) 67.8 g
68. B) 135 g
69. C) 16.9 g
70. D) 271 g
71. E) 333 g

 

Answer:  C

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

46) Nitrogen and hydrogen react together to form ammonia according to the following equation: ___N2(g) + ___H2(g) → ___NH3(g) (unbalanced) Balance the equation, and determine how many grams of hydrogen reactant would be required to produce 50.0 g of ammonia, assuming there is sufficient nitrogen available.

4. A) 4.46 g
5. B) 5.94 g
6. C) 4.81 g
7. D) 8.91 g
8. E) not enough information

 

Answer:  D

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

47) Nitrogen and hydrogen react together to form ammonia according to the equation: ___N2(g) + ___H2(g) → ___NH3(g) (unbalanced) Balance the equation, and determine how many grams of hydrogen reactant would be required to produce 25.0 g of ammonia, assuming there is sufficient nitrogen available.

2. A) 2.23 g
3. B) 4.46 g
4. C) 2.97 g
5. D) 2.40 g
6. E) not enough information

 

Answer:  B

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

48) When 3.0 mol CaCl2 dissolves in water, how many moles of ions are in solution?

1. A) 1.0 mole
2. B) 3.0 moles
3. C) 6.0 moles
4. D) 9.0 moles
5. E) 12 moles

 

Answer:  D

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions; Aqueous Solutions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Ions in Water (Electrolytes); Calculating Amounts of Reactant; Product (including solutions)

Accessibility:  Keyboard Navigation

 

49) When 5.0 g CaCl2 is dissolved in water, how many moles of ions are in solution?

1. A) 0.135 mole
2. B) 0.045 mole
3. C) 5.0 moles
4. D) 15.0 moles
5. E) 1660 moles

 

Answer:  A

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions; Aqueous Solutions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Ions in Water (Electrolytes); Calculating Amounts of Reactant; Product (including solutions)

Accessibility:  Keyboard Navigation

 

50) When 5.0 g CaCl2 is dissolved in enough water to make a 0.500 L solution, what is the molarity of ions in solution?

1. A) 0.135 M
2. B) 0.045 M
3. C) 0.270 M
4. D) 10.0 M
5. E) 2.50 M

 

Answer:  A

Difficulty: 3 Hard

Topic:  Stoichiometry and Chemical Reactions; Aqueous Solutions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Ions in Water (Electrolytes); Units of Concentration

Accessibility:  Keyboard Navigation

 

51) If you have eight bicycle wheels and five frames, how many bikes could you build (assuming that each bike requires one frame and two wheels), and what would be left over?

1. A) Four bikes could be built, and nothing would be left over.
2. B) Four bikes could be built, and one frame would be left over.
3. C) Five bikes could be built, and three wheels would be left over.
4. D) Five bikes could be built, and nothing would be left over.
5. E) Three bikes could be built, and two frames would be left over.

 

Answer:  B

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Limiting Reactant

Accessibility:  Keyboard Navigation

 

52) If you wish to make sandwiches which consist of two slices of bread, one ham slice, and three pickle slices, how many sandwiches could you make if you have 12 slices of bread, five slices of ham, and 20 pickle slices, and what would be left over?

1. A) Six sandwiches could be made, and two pickle slices would be left over.
2. B) Four sandwiches could be made, and four slices of bread and eight pickle slices would be left over.
3. C) Five sandwiches could be made, and two slices of bread and five pickle slices would be left over.
4. D) Twelve sandwiches could be made, and there would be no leftovers.
5. E) Five sandwiches could be made, and two slices of bread and no pickle slices would be left over.

 

Answer:  C

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Limiting Reactant

Accessibility:  Keyboard Navigation

 

53) A pamphlet requires one cover, 14 pieces of white paper, and three sheets of colored paper. How many pamphlets could be made, and what would be left over, if there are 50 covers, 500 sheets of white paper, and 100 sheets of colored paper available?

1. A) 33 pamphlets could be made, and one sheet of colored paper, 38 sheets of white paper, and 17 covers would be left over.
2. B) 50 pamphlets could be made, and there would be no leftovers.
3. C) 650 pamphlets could be made, and there would be no leftovers.
4. D) 34 pamphlets could be made, and 24 sheets of white paper and 16 covers would be left over.
5. E) 35 pamphlets could be made, and 10 sheets of white paper and 15 covers would be left over.

 

Answer:  A

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Limiting Reactant

Accessibility:  Keyboard Navigation

 

54) Consider the following reaction: CrCl3(s) + KCl(s) + 2H2SO4(l) → KCr(SO4)2(s) + 4HCl(g) green white colorless purple colorless solid solid liquid solid gas When the green solid is mixed with the white solid and the colorless liquid is added, the mixture starts to bubble and fume. When all action has stopped, a wet purple solid containing solid white specks remains. Which substance is the limiting reactant?

1. A) CrCl3
2. B) KCl
3. C) H2SO4
4. D) KCr(SO4)2
5. E) HCl

 

Answer:  A

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Limiting Reactant

Accessibility:  Keyboard Navigation

 

55) Consider the following reaction: Cr2O3(s) + 3CCl4(l) → 2CrCl3(s) + 3COCl2(g) green colorless purple colorless solid liquid solid gas When the green solid is mixed with the colorless liquid, the mixture starts to bubble and fume. When all action has stopped, a dry purple solid containing solid green specks remains. Which substance is the limiting reactant?

1. A) Cr2O3
2. B) CCl4
3. C) CrCl3
4. D) COCl2
5. E) there is no limiting reactant

 

Answer:  B

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Limiting Reactant

Accessibility:  Keyboard Navigation

 

56) Consider the following reaction: Cr2O3(s) + 3CCl4(l) → 2CrCl3(s) + 3COCl2(g) green colorless purple colorless solid liquid solid gas When the green solid is mixed with the colorless liquid, the mixture starts to bubble and fume. When all action has stopped, a wet purple solid remains. Which substance is the limiting reactant?

1. A) Cr2O3
2. B) CCl3
3. C) CrCl3
4. D) COCl2
5. E) there is no limiting reactant

 

Answer:  A

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Limiting Reactant

Accessibility:  Keyboard Navigation

 

57) Phosphorus trichloride can be made by the following reaction: P4(s) + 6Cl2(g) → 4PCl3(l) What is the maximum amount of phosphorus trichloride that can be formed if 10 molecules of P4 are mixed with 36 molecules of chlorine?

1. A) 4 molecules
2. B) 6 molecules
3. C) 12 molecules
4. D) 24 molecules
5. E) 46 molecules

 

Answer:  D

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

58) Phosphorus trichloride can be made by the following reaction: P4(s) + 6Cl2(g) → 4PCl3(l) What is the maximum amount of phosphorus trichloride that can be formed if 15 molecules of P4 are mixed with 42 molecules of chlorine?

1. A) 4 molecules
2. B) 12 molecules
3. C) 24 molecules
4. D) 28 molecules
5. E) 57 molecules

 

Answer:  D

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

59) Ammonia is usually made by the following reaction: N2(g) + 3H2(g) → 2NH3(g) What is the maximum amount of ammonia that can be formed if 25 molecules of nitrogen are mixed with 60 molecules of hydrogen?

1. A) 20 molecules
2. B) 25 molecules
3. C) 30 molecules
4. D) 40 molecules
5. E) 85 molecules

 

Answer:  D

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

60) Ammonia is usually made by the following reaction: N2(g) + 3H2(g) → 2NH3(g) What is the maximum amount of ammonia that can be formed if 30 molecules of nitrogen are mixed with 100 molecules of hydrogen?

1. A) 20 molecules
2. B) 30 molecules
3. C) 40 molecules
4. D) 60 molecules
5. E) 70 molecules

 

Answer:  D

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

61) The figure shows a molecular-level diagram of reactant molecules for the reaction   2H2(g) + O2(g) → 2H2O(l)

 

List the number and formulas of the molecules that should be present after the reaction takes place.

1. A) 2H2O + 6H2+ 2O2
2. B) 3H2O + 5H2+ O2
3. C) 4H2O + 4H2+ O2
4. D) 6H2O + 2H2+ O2
5. E) 6H2O + 2H2

 

Answer:  E

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant; Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

62) The figure shows a molecular-level diagram of reactant molecules for the reaction:  2C2H2(g) + 5O2(g) → 4CO2(g) + 2H2O(g)

 

 

List the number and formulas of the molecules that should be present after the reaction takes place.

1. A) 4CO2+ 2H2O
2. B) 4CO2+ 2H2O + 2C2H2
3. C) 4CO2+ 2H2O + 2C2H2+ 5O2
4. D) 6CO2+ 3H2O + 3O2
5. E) 8CO2+ 4H2O + 2C2H2

 

Answer:  E

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

63) Consider the reaction N2(g) + O2(g) → 2NO(g). The molecular image represents a mixture of N2(g) and O2(g) just before reaction occurs. What is the limiting reactant, and how much of the excess reactant remains after the reaction is complete? The image contains 2 N2 molecules and 4 O2 molecules.

 

1. A) N2(g), 1 O2(g)
2. B) N2(g), 2 O2(g)
3. C) N2(g), 3 O2(g)
4. D) O2(g), 1 N2(g)
5. E) N2(g), 0 O2(g)

 

Answer:  B

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

64) Consider the reaction N2(g) + 2O2(g) → 2NO2(g). The molecular image represents a mixture of N2(g) and O2(g) just before reaction occurs. What is the limiting reactant, and how much of the excess reactant remains after the reaction is complete? The image contains 3 N2 molecules and 9 O2 molecules.

 

 

1. A) N2(g), 6 O2(g)
2. B) O2(g), 1 N2(g)
3. C) N2(g), 3 O2(g)
4. D) O2(g), 2 N2(g)
5. E) N2(g), 7 O2(g)

 

Answer:  C

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

65) Nitrogen monoxide reacts with oxygen according to the following reaction:  2NO(g) + O2(g) → 2NO2(g) If 12 moles of nitrogen monoxide are combined with 10 moles of oxygen, how many moles of NO2 should form?

1. A) 2 moles
2. B) 5 moles
3. C) 6 moles
4. D) 10 moles
5. E) 12 moles

 

Answer:  E

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

66) Nitrogen monoxide reacts with oxygen according to the following reaction:  2NO(g) + O2(g) → 2NO2(g) If 10 moles of nitrogen monoxide are combined with 4 moles of oxygen, how many moles of NO2 should form?

1. A) 4 moles
2. B) 8 moles
3. C) 10 moles
4. D) 12 moles
5. E) 14 moles

 

Answer:  B

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

67) Aluminum reacts with oxygen according to the following reaction:  4Al(s) + 3O2(g) → 2Al2O3(s) If 24 moles of aluminum are combined with 12 moles of oxygen, how many moles of Al2O3 should form?

4. A) 4.0 moles
5. B) 8.0 moles
6. C) 6.0 moles
7. D) 5.0 moles
8. E) 26 moles

 

Answer:  B

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

68) Aluminum reacts with oxygen according to the following reaction:  4Al(s) + 3O2(g) → 2Al2O3(s) If 12 moles of aluminum are combined with 6 moles of oxygen, how many moles of Al2O3 should form?

1. A) 4 moles
2. B) 8 moles
3. C) 6 moles
4. D) 12 moles
5. E) 20 moles

 

Answer:  A

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

69) Consider the following reaction: 3NO2(g) + H2O(l) → 2HNO3(l) + NO(g) How many moles of NO2 are required to react with 1.50 moles of H2O to form 3.00 moles of HNO3?

1. A) 1.50 mol
2. B) 3.00 mol
3. C) 4.00 mol
4. D) 4.50 mol
5. E) 9.00 mol

 

Answer:  D

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

70) Consider the following reaction: 3NO2(g) + H2O(l) → 2HNO3(l) + NO(g) How many moles of the excess reactant remain if 4.00 moles of H2O and 10.00 moles of NO2 are mixed?

1. A) 0.67 mol H2O
2. B) 2.00 mol NO2
3. C) 3.33 mol H2O
4. D) 6.00 mol NO2
5. E) 8.00 mol NO2

 

Answer:  A

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

71) Iron metal reacts with chlorine gas according to the following equation: 2Fe(s) + 3Cl2(g) → 2FeCl3(s) If 35.0 g each of iron and chlorine are combined, how much FeCl3 should form?

1. A) 102 g
2. B) 155 g
3. C) 53.4 g
4. D) 80.0 g
5. E) 68.0 g

 

Answer:  C

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

72) Iron metal reacts with chlorine gas according to the following equation: 2Fe(s) + 3Cl2(g) → 2FeCl3(s) If 25.6 g each of iron and chlorine are combined, how much FeCl3 should form?

74. A) 74.3 g
75. B) 113 g
76. C) 39.0 g
77. D) 49.5 g
78. E) 26.0 g

 

Answer:  C

Difficulty: 3 Hard

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

73) In the process of obtaining lead from PbS, or galena, the galena is “roasted” (heated in the presence of oxygen), so that the following reaction occurs: 2PbS(s) + 3O2(g) → 2PbO(s) + 2SO2(g) If 50.0 g of PbS are mixed with 25.0 g of oxygen, how many grams of PbO should form?

1. A) 116 g
2. B) 46.6 g
3. C) 163 g
4. D) 69.9 g
5. E) 93.2 g

 

Answer:  B

Difficulty: 3 Hard

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

74) In the process of obtaining lead from PbS, or galena, the galena is “roasted” (heated in the presence of oxygen), so that the following reaction occurs:  2PbS(s) + 3O2(g) → 2PbO(s) + 2SO2(g) If 35.2 g of PbS is mixed with 15.5 g of oxygen, how many grams of PbO should form?

32. A) 32.8 g
33. B) 72.1 g
34. C) 105 g
35. D) 65.7 g
36. E) 49.2 g

 

Answer:  A

Difficulty: 3 Hard

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

75) What mass (in grams) of SF6 should be produced by the following reaction if 7.00 g of sulfur is mixed with 9.00 g of fluorine? S + 3F2 → SF6

24. A) 24.0
25. B) 6.40
26. C) 11.1
27. D) 32.0
28. E) 16.0

 

Answer:  C

Difficulty: 3 Hard

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Limiting Reactant

Accessibility:  Keyboard Navigation

 

76) If the theoretical yield for a reaction is 54.9 g, and 51.3 g of product are actually obtained, the percent yield is

1. A) 0.934%.
2. B) 93.4%.
3. C) 107%.
4. D) 3.60%.
5. E) not enough information given.

 

Answer:  B

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Reaction Yield

Accessibility:  Keyboard Navigation

 

77) If the theoretical yield for a reaction is 29.4 g, and 28.7 g of product are actually obtained, what is the percent yield?

1. A) 0.976%
2. B) 102%
3. C) 97.6%
4. D) 0.700%
5. E) not enough information given

 

Answer:  C

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Reaction Yield

Accessibility:  Keyboard Navigation

 

78) If the theoretical yield for a reaction is 72.3 g, and 65.2 g of product are actually obtained, what is the percent yield?

90. A) 90.2%
91. B) 0.902%
92. C) 7.10%
93. D) 111%
94. E) not enough information given

 

Answer:  A

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Reaction Yield

Accessibility:  Keyboard Navigation

 

79) Aluminum metal reacts with sulfuric acid according to the following equation: 2Al(s) + 3H2SO4(aq) → Al2(SO4)3(s) + 3H2(g) If 10.0 g of aluminum reacts with excess sulfuric acid, and 54.2 g of Al2(SO4)3 are collected, what is the percent yield of Al2(SO4)3?

63. A) 63.4%
64. B) 85.5%
65. C) 117%
66. D) 47.1%
67. E) not enough information given

 

Answer:  B

Difficulty: 3 Hard

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Reaction Yield

Accessibility:  Keyboard Navigation

 

80) Aluminum metal reacts with sulfuric acid according to the following equation: 2Al(s) + 3H2SO4(aq) → Al2(SO4)3(s) + 3H2(g) If 12.9 g of aluminum reacts with excess sulfuric acid, and 62.4 g of Al2(SO4)3 are collected, what is the percent yield of Al2(SO4)3?

81. A) 81.8%
82. B) 49.5%
83. C) 76.3%
84. D) 131%
85. E) not enough information given

 

Answer:  C

Difficulty: 3 Hard

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Reaction Yield

Accessibility:  Keyboard Navigation

 

 

81) Iron metal reacts with hydrochloric acid as follows: 2Fe(s) + 6HCl(aq) → 2FeCl3(aq) + 3H2(g) If 22.4 g of iron react with excess HCl, and 59.4 g of FeCl3 are collected, what is the percent yield of Al2(SO4)3?

65. A) 65.0%
66. B) 109%
67. C) 91.4%
68. D) 73.0%
69. E) not enough information given

 

Answer:  C

Difficulty: 3 Hard

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

82) Iron metal reacts with hydrochloric acid as follows: 2Fe(s) + 6HCl(aq) → 2FeCl3(aq) + 3H2(g) If 35.6 g of iron react with excess HCl, and 98.6 g of FeCl3 are collected, what is the percent yield of FeCl3?

1. A) 103%
2. B) 104%
3. C) 95.7%
4. D) 63.0%
5. E) not enough information given

 

Answer:  C

Difficulty: 3 Hard

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Reaction Yield

Accessibility:  Keyboard Navigation

 

 

83) Which of the following best describes an exothermic reaction?

1. A) Heat must be added to get the reaction to go
2. B) The temperature of the surroundings decreases
3. C) The potential energy of the reactants is greater than that of the surroundings
4. D) Matter is converted into energy
5. E) Heat is absorbed by the reaction from the surroundings

 

Answer:  C

Difficulty: 2 Medium

Topic:  Thermochemistry

Bloom’s:  1. Remember

Gradable:  automatic

Subtopic:  System/Surroundings and Heat/Work

Accessibility:  Keyboard Navigation

 

84) Which of the following processes is exothermic?

1. A) ice melting in a beverage
2. B) dry ice (solid CO2) converting to a gas at room temperature
3. C) evaporation of water from a mud puddle
4. D) burning propane in a barbeque grill
5. E) wax melting on the top of a burning candle

 

Answer:  D

Difficulty: 2 Medium

Topic:  Thermochemistry

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  System/Surroundings and Heat/Work

Accessibility:  Keyboard Navigation

 

85) Which of the following is an exothermic process?

1. A) ice melting
2. B) water evaporating
3. C) boiling soup
4. D) condensation of water vapor
5. E) Ammonium thiocyanate and barium hydroxide are mixed, resulting in a decrease in temperature of the surroundings

 

Answer:  D

Difficulty: 2 Medium

Topic:  Thermochemistry

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  System/Surroundings and Heat/Work

Accessibility:  Keyboard Navigation

86) Which of the following processes is endothermic?

1. A) burning gasoline in an internal combustion engine
2. B) evaporation of perspiration on your skin
3. C) burning wood in a fireplace
4. D) condensing steam on a mirror
5. E) hot coffee cooling down as it sits on the table

 

Answer:  B

Difficulty: 2 Medium

Topic:  Thermochemistry

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  System/Surroundings and Heat/Work

Accessibility:  Keyboard Navigation

 

87) Which of the following is an exothermic process?

1. A) ice melting
2. B) water evaporating
3. C) boiling soup
4. D) condensation of water vapor
5. E) Ammonium thiocyanate and barium hydroxide are mixed, resulting in a decrease in temperature

 

Answer:  D

Difficulty: 2 Medium

Topic:  Thermochemistry

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  System/Surroundings and Heat/Work

Accessibility:  Keyboard Navigation

 

88) Which of the following processes is exothermic?

1. A) boiling water to make tea
2. B) cooking an egg
3. C) heating food in a microwave oven
4. D) an acid and base reacting together, and causing the solution to become warm
5. E) water in a swimming pool getting warmer in the sun

 

Answer:  D

Difficulty: 2 Medium

Topic:  Thermochemistry

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  System/Surroundings and Heat/Work

Accessibility:  Keyboard Navigation

89) The following reaction absorbs 393 kJ of heat for each mole of CO2 that reacts. CO2(g) → C(s) + O2(g) This reaction

1. A) is endothermic and has a positive value of q.
2. B) is exothermic and has a positive value of q.
3. C) is endothermic and has a negative value of q.
4. D) is exothermic and has a negative value of q.

 

Answer:  A

Difficulty: 2 Medium

Topic:  Thermochemistry

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Enthalpy (Heats of Reaction)

Accessibility:  Keyboard Navigation

 

90) The following reaction releases 2800 kJ of heat for each mole of C6H12O6 that reacts. C6H12O6(s) + 6O2(g) → 6CO2(g) + 6H2O(l) This reaction is

1. A) endothermic and has a positive value of q.
2. B) exothermic and has a positive value of q.
3. C) endothermic and has a negative value of q.
4. D) exothermic and has a negative value of q.

 

Answer:  D

Difficulty: 2 Medium

Topic:  Thermochemistry

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Enthalpy (Heats of Reaction)

Accessibility:  Keyboard Navigation

 

 

91) Consider the following specific heats of metals.

 

Metal	Specific Heat [J/(gºC)]
copper	0.377
calcium	0.656
aluminum	0.895
iron	0.448
lead	0.129

 

If the same amount of heat is added to 25.0 g of each of these metals, all at the same initial temperature, which metal will have the highest final temperature?

1. A) copper
2. B) calcium
3. C) aluminum
4. D) iron
5. E) lead

 

Answer:  E

Difficulty: 2 Medium

Topic:  Thermochemistry

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Calorimetry (Measuring Heats of Reaction)

Accessibility:  Keyboard Navigation

 

 

92) Consider the following specific heats of metals.

 

Metal	Specific Heat [J/(gºC)]
copper	0.377
calcium	0.656
aluminum	0.895
iron	0.448
lead	0.129

 

If the same amount of heat is added to 50.0 g of each of these metals, all at the same initial temperature, which metal will have the lowest final temperature?

1. A) copper
2. B) calcium
3. C) aluminum
4. D) iron
5. E) lead

 

Answer:  C

Difficulty: 2 Medium

Topic:  Thermochemistry

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Calorimetry (Measuring Heats of Reaction)

Accessibility:  Keyboard Navigation

 

 

93) If 75.0 J of heat energy is added to 25.0 g samples of different metals. Given their specific heat values, rank the metals in order from least to greatest final temperature.

 

Metal	Specific Heat [J/(gºC)]
Au	0.129
Ag	0.234
Al	0.895
Cr	0.450
Cu	0.377

 

1. A) Au < Ag < Cu < Cr < Al
2. B) Al < Cr < Cu < Ag < Au
3. C) Au < Ag < Al < Cr < Cu
4. D) Cr < Cu < Al < Ag < Au
5. E) none of these—all final temperatures would be equal

 

Answer:  B

Difficulty: 2 Medium

Topic:  Thermochemistry

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Calorimetry (Measuring Heats of Reaction)

Accessibility:  Keyboard Navigation

 

 

94) An equal quantity of heat is transferred to 10.0 g samples of different substances. Given their specific heat values, rank the substances in order from least to greatest final temperature.

 

Substance	Specific Heat [J/(g°C)]
liquid water	4.184
concrete	0.88
asphalt	0.920
glass	0.84
iron	0.448

 

1. A) iron < glass < concrete < asphalt < water
2. B) water < asphalt < concrete < glass < iron
3. C) asphalt < concrete < glass < iron < water
4. D) iron < concrete < glass < asphalt < water
5. E) water < concrete < asphalt < glass < iron

 

Answer:  B

Difficulty: 2 Medium

Topic:  Thermochemistry

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Calorimetry (Measuring Heats of Reaction)

Accessibility:  Keyboard Navigation

 

95) A carton of low-fat yogurt says it has 1.70 x 102 Calories. What is the equivalent amount of energy in units of joules?

1. A) 711 J
2. B) 7.11 x 105J
3. C) 4.06 x 104J
4. D) 406 J
5. E) 40.6 J

 

Answer:  B

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Dimensional Analysis; Units of Energy

Accessibility:  Keyboard Navigation

 

 

96) A can of soda has 1.50 x 102 Calories. Convert this energy to units of joules.

1. A) 628 J
2. B) 6280 J
3. C) 35.9 J
4. D) 3.59 x 104J
5. E) 6.28 x 105J

 

Answer:  E

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Dimensional Analysis; Units of Energy

Accessibility:  Keyboard Navigation

 

97) A 43 g serving of a chocolate candy has 2.10 x 102 Calories. Convert this energy to units of joules.

1. A) 879 J
2. B) 8.79 x 105J
3. C) 50.2 J
4. D) 5.02 x 104J
5. E) 8.79 x 103J

 

Answer:  B

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Dimensional Analysis; Units of Energy

Accessibility:  Keyboard Navigation

 

98) When carbon dioxide is formed from its elements, 393.5 kJ of energy is released. Convert this energy to units of calories.

9. A) 9.405 x 104cal
10. B) 94.05 cal
11. C) 0.3935 cal
12. D) 1.646 x 103cal
13. E) 1.646 x 106cal

 

Answer:  A

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Dimensional Analysis; Units of Energy

Accessibility:  Keyboard Navigation

99) When sulfur dioxide is formed from its elements, 296.8 kJ of energy is released. Convert this energy to units of calories.

70. A) 70.94 cal
71. B) 7.094 x 104cal
72. C) 0.2968 cal
73. D) 1.242 x 103cal
74. E) 1.242 x 106cal

 

Answer:  B

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Dimensional Analysis; Units of Energy

Accessibility:  Keyboard Navigation

 

100) An energy input of 227 kJ is required to form acetylene from its elements. Convert this energy to units of calories.

9. A) 9.50 x 102cal
10. B) 9.50 x 105cal
11. C) 0.227 cal
12. D) 54.3 cal
13. E) 5.43 x 104cal

 

Answer:  E

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Dimensional Analysis; Units of Energy

Accessibility:  Keyboard Navigation

 

 

 

101) Equal masses of ice at 0°C and water at 100°C are mixed in an insulated container. Estimate the final temperature of the mixture.

1. A) between 51 and 99°C
2. B) between 1 and 49ºC
3. C) 50°C
4. D) 0°C
5. E) 100°C

 

Answer:  B

Difficulty: 3 Hard

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calorimetry (Measuring Heats of Reaction)

Accessibility:  Keyboard Navigation

102) How much heat energy would be needed to raise the temperature of a 15.0 g sample of iron [C = 0.448 J/(g°C)] from 22.0°C to 100.0°C?

34. A) 34.9 J
35. B) 672 J
36. C) 524 J
37. D) 1.17 x 103J
38. E) not enough information given

 

Answer:  C

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calorimetry (Measuring Heats of Reaction)

Accessibility:  Keyboard Navigation

 

 

 

103) How much heat energy would be needed to raise the temperature of a 22.3 g sample of aluminum [(C = 0.895 (J/g°C)] from 22.5°C to 55.0°C?

20. A) 20.0 J
21. B) 649 J
22. C) 725 J
23. D) 8.10 x 102J
24. E) not enough information given

 

Answer:  B

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calorimetry (Measuring Heats of Reaction)

Accessibility:  Keyboard Navigation

 

104) How much heat energy would be needed to raise the temperature of a 32.0 g sample of gold [C = 0.129 (J/g°C)] from 21.8°C to 75.0°C?

3. A) 3.10 x 102J
4. B) 1.32 x 104J
5. C) 2.20 x 102J
6. D) 90.0 J
7. E) not enough information given

 

Answer:  C

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calorimetry (Measuring Heats of Reaction)

Accessibility:  Keyboard Navigation

 

 

105) What is the heat change when a 53.5 g sample of water [Cwater = 4.184 J/(g°C)] is cooled from 98.0°C to 23.2°C?

1. A) 1.67 x 104J
2. B) −1.67 x 104J
3. C) 2.19 x 104J
4. D) −956 J
5. E) not enough information given

 

Answer:  B

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calorimetry (Measuring Heats of Reaction)

Accessibility:  Keyboard Navigation

 

106) What is the heat change when a 26.8 g sample of water [Cwater = 4.184 J/(g°C)] is cooled from 75.6°C to 22.1°C?

6. A) 6.00 x 103J
7. B) −6.00 x 103J
8. C) 1.43 x 103J
9. D) −1.43 x 103J
10. E) not enough information given

 

Answer:  B

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calorimetry (Measuring Heats of Reaction)

Accessibility:  Keyboard Navigation

 

 

107) What is the heat change when a 225 g sample of olive oil [Cwater = 1.79 J/(g°C)] is cooled from 95.8°C to 52.1°C?

9. A) 9.83 x 103J
10. B) −9.83 x 103J
11. C) −1.76 x 104J
12. D) 1.76 x 104J
13. E) not enough information given

 

Answer:  A

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calorimetry (Measuring Heats of Reaction)

Accessibility:  Keyboard Navigation

 

108) A 5.00 g sample of a brownie was burned in a bomb calorimeter containing 2025 g of water. The temperature of the water increased from 23.50°C to 33.47°C. How much heat, in joules, did the brownie release when it burned? [Cwater = 4.184 J/(g°C)]

1. A) 1.99 x 105J
2. B) 2.80 x 105J
3. C) 4.92 x 102J
4. D) 8.45 x 104J
5. E) 7.00 x 102J

 

Answer:  D

Difficulty: 2 Medium

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calorimetry (Measuring Heats of Reaction)

Accessibility:  Keyboard Navigation

 

 

109) A 2.50 g sample of pitted prunes was burned in a bomb calorimeter containing 2110 g of water. The temperature of the water increased from 22.50°C to 25.76°C. How much heat, in joules, did the prune sample release when it burned? [Cwater = 4.184 J/(g°C)]

1. A) 1.99 x 105J
2. B) 2.27 x 105J
3. C) 2.88 x 104J
4. D) 2.35 x 102J
5. E) 2.69 x 102J

 

Answer:  C

Difficulty: 2 Medium

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calorimetry (Measuring Heats of Reaction)

Accessibility:  Keyboard Navigation

 

110) A 3.50 g sample of rice was burned in a bomb calorimeter containing 1980 g of water. The temperature of the water increased from 22.75°C to 28.88°C. How much heat, in joules, did the rice sample release when it burned? [Cwater = 4.184 J/(g°C)]

1. A) 1.88 x 105J
2. B) 2.39 x 105J
3. C) 5.08 x 104J
4. D) 3.33 x 102J
5. E) 4.22 x 102J

 

Answer:  C

Difficulty: 2 Medium

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Calorimetry (Measuring Heats of Reaction)

Accessibility:  Keyboard Navigation

 

 

111) The q value for the following reaction is 178.0 kJ for every mole of CaCO3 that reacts: CaCO3(s) → CaO(s) + CO2(g) How much heat would be required to decompose 4.00 mol CaCO3(s), and is the reaction endothermic or exothermic?

1. A) 712 kJ; exothermic
2. B) 712 kJ; endothermic
3. C) 178 kJ; exothermic
4. D) 44.5 kJ; endothermic
5. E) 44.5 kJ; exothermic

 

Answer:  B

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  automatic

Subtopic:  Enthalpy (Heats of Reaction)

Accessibility:  Keyboard Navigation

 

112) The coefficients of a balanced equation can be understood to represent either relative numbers of molecules or moles.

 

Answer:  TRUE

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

113) The coefficients of a balanced equation can be understood to represent either relative numbers of moles or relative mass.

 

Answer:  FALSE

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Writing and Balancing Chemical Equations

Accessibility:  Keyboard Navigation

 

 

114) The number of moles of reactant molecules must always equal the number of moles of product molecules in a balanced equation.

 

Answer:  FALSE

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Calculating Amounts of Reactant and Product (including solutions)

Accessibility:  Keyboard Navigation

 

115) The limiting reactant in a chemical reaction is always the reactant which is present in the least amount in terms of mass.

 

Answer:  FALSE

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Limiting Reactant

Accessibility:  Keyboard Navigation

 

116) When calculating the percent yield for a reaction, the only information necessary is the mass of each reactant.

 

Answer:  FALSE

Difficulty: 1 Easy

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Reaction Yield

Accessibility:  Keyboard Navigation

 

117) A calorie used by nutritionists, 1 Calorie, is equal to 1000 cal or 1 kcal used by chemists.

 

Answer:  FALSE

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  1. Remember

Gradable:  automatic

Subtopic:  Units of Energy

Accessibility:  Keyboard Navigation

 

 

118) One calorie is the amount of heat energy required to raise the temperature of 10.0 g of water by 1°C.

 

Answer:  FALSE

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  1. Remember

Gradable:  automatic

Subtopic:  Units of Energy

Accessibility:  Keyboard Navigation

 

119) When a substance cools from a high temperature to a low temperature, its heat change value will have a negative sign.

 

Answer:  FALSE

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  System/Surroundings and Heat/Work

Accessibility:  Keyboard Navigation

 

120) The specific heat of a substance is the amount of heat energy that is needed to cause the substance to melt.

 

Answer:  FALSE

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  System/Surroundings and Heat/Work

Accessibility:  Keyboard Navigation

 

121) In a bomb calorimeter, the bomb itself, the water surrounding it, and the thermometer would be considered part of the “system.”

 

Answer:  FALSE

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Calorimetry (Measuring Heats of Reaction)

Accessibility:  Keyboard Navigation

 

 

122) When fats or other foods are burned in a bomb calorimeter, the calorimeter absorbs heat, so the reaction is endothermic.

 

Answer:  FALSE

Difficulty: 2 Medium

Topic:  Thermochemistry

Bloom’s:  2. Understand

Gradable:  automatic

Subtopic:  Calorimetry (Measuring Heats of Reaction)

Accessibility:  Keyboard Navigation

 

123) When blue copper(II) sulfate pentahydrate is heated, it decomposes according to the equation given below, forming light blue copper(II) sulfate and water vapor. CuSO4·5H2O(s) → CuSO4(s) + 5H2O(g) If a 5.00 g sample of CuSO4·5H2O is heated, what mass of CuSO4 will be formed when the reaction is complete? Report your answer with the correct number of significant figures and correct units.

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  manual

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Scientific Notation; Significant Figures

Accessibility:  Keyboard Navigation

 

124) When potassium metal is exposed to air, it forms a coating of potassium oxide, according to the following equation: 4K(s) + O2(g) → 2K2O(s) If a piece of potassium gains 0.354 g, assuming this gain can be attributed to the above reaction with oxygen, what mass of oxygen reacted with the potassium? Report your answer with the correct number of significant figures and correct units.

Difficulty: 3 Hard

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  manual

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Scientific Notation; Significant Figures

Accessibility:  Keyboard Navigation

 

 

125) When potassium metal is exposed to air, it forms a coating of potassium oxide, according to the following equation: 4K(s) + O2(g) → 2K2O(s) If a piece of potassium gains 0.354 g, assuming this gain can be attributed to the above reaction with oxygen, what mass of potassium reacted? Report your answer with the correct number of significant figures and correct units.

Difficulty: 3 Hard

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  manual

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Scientific Notation; Significant Figures

Accessibility:  Keyboard Navigation

 

126) When potassium metal is exposed to air, it forms a coating of potassium oxide, according to the following equation: 4K(s) + O2(g) → 2K2O(s) If a piece of potassium gains 0.354 g, assuming this gain can be attributed to the above reaction with oxygen, what mass of K2O formed? Report your answer with the correct number of significant figures and correct units.

Difficulty: 3 Hard

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  manual

Subtopic:  Scientific Notation; Significant Figures

Accessibility:  Keyboard Navigation

 

127) The combustion of octane is described by the following balanced equation: 2C8H18(l) + 25O2(g) → 16CO2(g) + 18H2O(g) If 50.0 g of each reactant are available to react, how much CO2 should form? Report your answer with the correct number of significant figures and correct units.

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  manual

Subtopic:  Limiting Reactant; Scientific Notation; Significant Figures

Accessibility:  Keyboard Navigation

128) An aqueous solution containing 15.0 g of NaOH is mixed with an aqueous solution containing 15.0 g of H2SO4. Is sodium hydroxide or sulfuric acid the limiting reactant?

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  manual

Subtopic:  Writing and Balancing Chemical Equations; Limiting Reactant

Accessibility:  Keyboard Navigation

 

 

 

129) An aqueous solution containing 15.0 g of NaOH is mixed with an aqueous solution containing 15.0 g of H2SO4. Will the solution be acidic or basic when the reaction is complete?

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  manual

Subtopic:  Writing and Balancing Chemical Equations; Limiting Reactant

Accessibility:  Keyboard Navigation

 

130) In photosynthesis, plants convert carbon dioxide and water into glucose, C6H12O6, according to the reaction: 6CO2(g) + 6H2O(l) → 6O2(g) + C6H12O6(g) How many grams of glucose can be synthesized from 117 g of CO2, assuming there is sufficient water to react with all of the CO2? Report your answer with the correct number of significant figures and correct units.

Difficulty: 2 Medium

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  manual

Subtopic:  Calculating Amounts of Reactant and Product (including solutions); Scientific Notation; Significant Figures

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131) How much heat must be added to 125 g of copper [C = 0.377 J/(g°C)] at 25.0°C to raise its temperature to 78.4°C? Report your answer with the correct number of significant figures and correct units.

Difficulty: 1 Easy

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  manual

Subtopic:  System/Surroundings and Heat/Work; Scientific Notation; Significant Figures

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132) The burning of a 2.50 g sample of pizza in a bomb calorimeter gives off 2.53 x 104 J of energy. If the calorimeter contains 2440 g of water, what was the temperature change of the water? [Cwater = 4.184 J/(g°C)] Report your answer with the correct number of significant figures.

Difficulty: 3 Hard

Topic:  Thermochemistry

Bloom’s:  3. Apply

Gradable:  manual

Subtopic:  Calorimetry (Measuring Heats of Reaction); Scientific Notation; Significant Figures

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133) In photosynthesis, plants convert carbon dioxide and water into glucose, C6H12O6, according to the reaction: 6CO2(g) + 6H2O(l) → 6O2(g) + C6H12O6(g) If 75.2 g of glucose are obtained when 131 g of CO2 react in the presence of excess H2O, what is the percent yield of the reaction? Report your answer with the correct number of significant figures.

Difficulty: 3 Hard

Topic:  Stoichiometry and Chemical Reactions

Bloom’s:  3. Apply

Gradable:  manual

Subtopic:  Reaction Yield; Calorimetry (Measuring Heats of Reaction); Scientific Notation; Significant Figures

Accessibility:  Keyboard Navigation