Question 1

O2 can be produced by the reaction 2KClO3(s) → 2KCl(s) + 3O2(g). In one experiment, 0.312 g of O2 was formed. How much KCl was produced?

Accepted Answer

A)  0.484 g 
B)  0.797 g 
C)  1.19 g 
D)  1.79 g 
A)  0.484 g 
B)  0.797 g 
C)  1.19 g 
D)  1.79 g A

Question 2

Which of the following is reduction?

Accepted Answer

A)  gain of electrons 
B)  loss of hydrogen 
C)  gain of oxygen 
D)  none of these 
A)  gain of electrons 
B)  loss of hydrogen 
C)  gain of oxygen 
D)  none of these A

Question 3

To which of the following is the term molecular weight applicable?

Accepted Answer

A)  ionic compounds 
B)  covalent compounds 
C)  both ionic and covalent compounds 
D)  neither ionic or covalent compounds 
A)  ionic compounds 
B)  covalent compounds 
C)  both ionic and covalent compounds 
D)  neither ionic or covalent compounds B

Question 4

Which of the following is true of a chemical reaction?

Accepted Answer

A)  In a chemical reaction, the number of moles of product always equals the number of moles of reactants. 
B)  In a chemical reaction, the mass of the products always equals the mass of the starting materials that have reacted. 
C)  In a chemical reaction, the number of moles of product always equals the number of moles of reactants, and the mass of products always equals the mass of the starting materials that have reacted. 
D)  In a chemical reaction, the number of moles of product does not always equal the number of moles of reactants, and the mass of products does not always equal the mass of the starting materials that have reacted. 
A)  In a chemical reaction, the number of moles of product always equals the number of moles of reactants. 
B)  In a chemical reaction, the mass of the products always equals the mass of the starting materials that have reacted. 
C)  In a chemical reaction, the number of moles of product always equals the number of moles of reactants, and the mass of products always equals the mass of the starting materials that have reacted. 
D)  In a chemical reaction, the number of moles of product does not always equal the number of moles of reactants, and the mass of products does not always equal the mass of the starting materials that have reacted.

Question 5

How many calories are required to heat 520 g of copper from 30°C to 800°C? The specific heat of copper is 0.092 cal/g·°C.

Accepted Answer

A)  38,272 cal 
B)  36,837 cal 
C)  1,435 cal 
D)  1,276 cal 
A)  38,272 cal 
B)  36,837 cal 
C)  1,435 cal 
D)  1,276 cal

Question 6

The synthesis of a certain drug requires four steps. The first three steps were relatively easy with percent yields of 97.1%, 94.3%, and 92.8%, respectively. However, the last step was very difficult, with a percent yield of 72.7%. What was the overall percent yield?

Accepted Answer

A)  	27. 9% 
B)  	61.8% 
C)  	72.7% 
D)  	85.0% 
A)  	27. 9% 
B)  	61.8% 
C)  	72.7% 
D)  	85.0%

Question 7

Lime, CaO, is produced by the reaction CaCO3(s) → CaO(s) + CO2(g). What weight of CaO is obtained by the decomposition of 38.7 g of CaCO3?

Accepted Answer

A)  15.5 g 
B)  17.0 g 
C)  21.7 g 
D)  23.2 g 
A)  15.5 g 
B)  17.0 g 
C)  21.7 g 
D)  23.2 g

Question 8

Which of the following statements is true of the balanced equation 3H2(g) + N2(g) → 2NH3(g)?

Accepted Answer

A)  Three grams of hydrogen react with one gram of nitrogen to form two grams of ammonia. 
B)  Three moles of hydrogen react with one mole of nitrogen to form two moles of ammonia. 
C)  Three moles of hydrogen react with one gram of nitrogen to form two grams of ammonia, and three moles of hydrogen react with one mole of nitrogen to form two moles of ammonia. 
D)  None of these are true. 
A)  Three grams of hydrogen react with one gram of nitrogen to form two grams of ammonia. 
B)  Three moles of hydrogen react with one mole of nitrogen to form two moles of ammonia. 
C)  Three moles of hydrogen react with one gram of nitrogen to form two grams of ammonia, and three moles of hydrogen react with one mole of nitrogen to form two moles of ammonia. 
D)  None of these are true.

Question 9

Which of the following represents the correct set of spectator ions in the equation Cu2+(aq) + 2Cl-(aq) + 2K+(aq) + S2- (aq) → CuS(s) + 2K+(aq) + 2Cl-(aq)?

Accepted Answer

A)  Cu2+, Cl- 
B)  K+, Cl- 
C)  K+, S2- 
D)  Cu2+, S2- 
A)  Cu2+, Cl- 
B)  K+, Cl- 
C)  K+, S2- 
D)  Cu2+, S2-

Question 10

O2 can be produced by the reaction 2KClO3(s) → KCl(s) + 3O2(g). In one experiment, 0.312 g of O2 was formed. How much KClO3 was decomposed?

Accepted Answer

A)  0.484 g 
B)  0.797 g 
C)  1.19 g 
D)  1.79 g 
A)  0.484 g 
B)  0.797 g 
C)  1.19 g 
D)  1.79 g

Question 11

Which of the following definitions of reduction is generally most useful when dealing with ionic materials?

Accepted Answer

A)  Reduction is the gain of electrons. 
B)  Reduction is the gain of hydrogen. 
C)  Reduction is the loss of oxygen. 
D)  None; these are all equally useful. 
A)  Reduction is the gain of electrons. 
B)  Reduction is the gain of hydrogen. 
C)  Reduction is the loss of oxygen. 
D)  None; these are all equally useful.

Question 12

You have a sample of 3.01 × 1023 atoms of silver. How much does this sample weigh?

Accepted Answer

A)  0.0500 g 
B)  2.00 g 
C)  53.9 g 
D)  107.9 g 
A)  0.0500 g 
B)  2.00 g 
C)  53.9 g 
D)  107.9 g

Question 13

Ethanol is produced industrially by the acid-catalyzed reaction of ethylene with water. The balanced equation for this reaction is as follows: C2H4(g) + H2O(g) → C2H5OH(l)
If water is present in excess, how many moles of ethanol can be produced from 7.24 mol of ethylene?

Accepted Answer

A)  7.24 
B)  14.5 
C)  28.0 
D)  46.0 
A)  7.24 
B)  14.5 
C)  28.0 
D)  46.0

Question 14

Which of the following is the SI unit for heat?

Accepted Answer

A)  calorie 
B)  kilocalorie 
C)  joule 
D)  watt 
A)  calorie 
B)  kilocalorie 
C)  joule 
D)  watt

Question 15

What is the molecular weight of sucrose, C12H22O11?

Accepted Answer

A)  180.2 amu 
B)  319.6 amu 
C)  342.3 amu 
D)  360.4 amu 
A)  180.2 amu 
B)  319.6 amu 
C)  342.3 amu 
D)  360.4 amu

Question 16

Consider the following representation of a voltaic cell.   This voltaic cell is represented by the following reaction: Mg(s) + Cu2+(aq) → Cu(s) + Mg2+(aq)
What is the identity of the ion in the solution shown in the diagram?

Accepted Answer

A)  Mg 
B)  Cu 
C)  Mg2+ 
D)  Cu2+ 
A)  Mg 
B)  Cu 
C)  Mg2+ 
D)  Cu2+

Question 17

A black precipitate of copper sulfide, CuS, is formed when a solution of Cu(II) chloride, CuCl2, is added to a solution of potassium sulfide, K2S. Which of the following ionic equations for this reaction includes the spectator ions as well?

Accepted Answer

A)  CuCl2(aq) + K2S(aq) → CuS(s) + 2KCl(aq) 
B)  Cu2+(aq) + Cl22-(aq) + K22+(aq) + S2-(aq) → CuS(s) + K22+(aq) + Cl22-(aq) 
C)  Cu2+(aq) + 2Cl-(aq) + 2K+(aq) + S2-(aq) → CuS(s) + 2K+(aq) + 2Cl- (aq) 
D)  Cu2+(aq) + S2-(aq) → CuS(s) 
A)  CuCl2(aq) + K2S(aq) → CuS(s) + 2KCl(aq) 
B)  Cu2+(aq) + Cl22-(aq) + K22+(aq) + S2-(aq) → CuS(s) + K22+(aq) + Cl22-(aq) 
C)  Cu2+(aq) + 2Cl-(aq) + 2K+(aq) + S2-(aq) → CuS(s) + 2K+(aq) + 2Cl- (aq) 
D)  Cu2+(aq) + S2-(aq) → CuS(s)

Question 18

The metabolism of one mole of glucose, C6H12O6, releases 670 kcal of heat. How much heat is released by the combustion of 0.300 moles of glucose?

Accepted Answer

A)  186 kcal 
B)  201 kcal 
C)  2.23 × 103 kcal 
D)  2.41 × 103 kcal 
A)  186 kcal 
B)  201 kcal 
C)  2.23 × 103 kcal 
D)  2.41 × 103 kcal

Question 19

Which of the following is true of respiration?

Accepted Answer

A)  It is the conversion of iron to iron oxide. 
B)  It is the conversion of colored compounds to colorless compounds. 
C)  It is the production of energy in humans and animals. 
D)  It is the generation of electricity in a voltaic cell. 
A)  It is the conversion of iron to iron oxide. 
B)  It is the conversion of colored compounds to colorless compounds. 
C)  It is the production of energy in humans and animals. 
D)  It is the generation of electricity in a voltaic cell.

Question 20

When solutions of AgNO3 and NaCl react, the balanced molecular equation is as follows: AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq)
How much AgCl is produced when 3.10 g of AgNO3 and 0.600 g of NaCl react?

Accepted Answer

A)  1.47 g 
B)  2.23 g 
C)  2.62 g 
D)  3.70 g 
A)  1.47 g 
B)  2.23 g 
C)  2.62 g 
D)  3.70 g

Exam 4: Chemical Reactions

O2 can be produced by the reaction 2KClO3(s) → 2KCl(s) + 3O2(g). In one experiment, 0.312 g of O2 was formed. How much KCl was produced?

Which of the following is reduction?

To which of the following is the term molecular weight applicable?

Which of the following is true of a chemical reaction?

How many calories are required to heat 520 g of copper from 30°C to 800°C? The specific heat of copper is 0.092 cal/g·°C.

The synthesis of a certain drug requires four steps. The first three steps were relatively easy with percent yields of 97.1%, 94.3%, and 92.8%, respectively. However, the last step was very difficult, with a percent yield of 72.7%. What was the overall percent yield?

Lime, CaO, is produced by the reaction CaCO3(s) → CaO(s) + CO2(g). What weight of CaO is obtained by the decomposition of 38.7 g of CaCO3?

Which of the following statements is true of the balanced equation 3H2(g) + N2(g) → 2NH3(g)?

Which of the following represents the correct set of spectator ions in the equation Cu2+(aq) + 2Cl-(aq) + 2K+(aq) + S2- (aq) → CuS(s) + 2K+(aq) + 2Cl-(aq)?

O2 can be produced by the reaction 2KClO3(s) → KCl(s) + 3O2(g). In one experiment, 0.312 g of O2 was formed. How much KClO3 was decomposed?

Which of the following definitions of reduction is generally most useful when dealing with ionic materials?

You have a sample of 3.01 × 1023 atoms of silver. How much does this sample weigh?

Ethanol is produced industrially by the acid-catalyzed reaction of ethylene with water. The balanced equation for this reaction is as follows: C2H4(g) + H2O(g) → C2H5OH(l) If water is present in excess, how many moles of ethanol can be produced from 7.24 mol of ethylene?

Which of the following is the SI unit for heat?

What is the molecular weight of sucrose, C12H22O11?

Consider the following representation of a voltaic cell. This voltaic cell is represented by the following reaction: Mg(s) + Cu2+(aq) → Cu(s) + Mg2+(aq) What is the identity of the ion in the solution shown in the diagram?

A black precipitate of copper sulfide, CuS, is formed when a solution of Cu(II) chloride, CuCl2, is added to a solution of potassium sulfide, K2S. Which of the following ionic equations for this reaction includes the spectator ions as well?

The metabolism of one mole of glucose, C6H12O6, releases 670 kcal of heat. How much heat is released by the combustion of 0.300 moles of glucose?

Which of the following is true of respiration?

When solutions of AgNO3 and NaCl react, the balanced molecular equation is as follows: AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq) How much AgCl is produced when 3.10 g of AgNO3 and 0.600 g of NaCl react?

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O₂ can be produced by the reaction 2KClO₃(s) → 2KCl(s) + 3O₂(g). In one experiment, 0.312 g of O₂ was formed. How much KCl was produced?

Lime, CaO, is produced by the reaction CaCO₃(s) → CaO(s) + CO₂(g). What weight of CaO is obtained by the decomposition of 38.7 g of CaCO₃?

Which of the following statements is true of the balanced equation 3H₂(g) + N₂(g) → 2NH₃(g)?

Which of the following represents the correct set of spectator ions in the equation Cu²⁺(aq) + 2Cl^-(aq) + 2K⁺(aq) + S^2- (aq) → CuS(s) + 2K⁺(aq) + 2Cl^-(aq)?

O₂ can be produced by the reaction 2KClO₃(s) → KCl(s) + 3O₂(g). In one experiment, 0.312 g of O₂ was formed. How much KClO₃ was decomposed?

You have a sample of 3.01 × 10²³ atoms of silver. How much does this sample weigh?

Ethanol is produced industrially by the acid-catalyzed reaction of ethylene with water. The balanced equation for this reaction is as follows: C₂H₄(g) + H₂O(g) → C₂H₅OH(l) If water is present in excess, how many moles of ethanol can be produced from 7.24 mol of ethylene?

What is the molecular weight of sucrose, C₁₂H₂₂O₁₁?

Consider the following representation of a voltaic cell. This voltaic cell is represented by the following reaction: Mg(s) + Cu²⁺(aq) → Cu(s) + Mg²⁺(aq) What is the identity of the ion in the solution shown in the diagram?

A black precipitate of copper sulfide, CuS, is formed when a solution of Cu(II) chloride, CuCl₂, is added to a solution of potassium sulfide, K₂S. Which of the following ionic equations for this reaction includes the spectator ions as well?

The metabolism of one mole of glucose, C₆H₁₂O₆, releases 670 kcal of heat. How much heat is released by the combustion of 0.300 moles of glucose?

When solutions of AgNO₃ and NaCl react, the balanced molecular equation is as follows: AgNO₃(aq) + NaCl(aq) → AgCl(s) + NaNO₃(aq) How much AgCl is produced when 3.10 g of AgNO₃ and 0.600 g of NaCl react?