Chemical Reactions Ch.5 Test Bank Docx 4th Edition

General, Organic and Biological Chemistry, 4e (Smith)

Chapter 5 Chemical Reactions

1) The law of conservation of mass states that ________.

A) atoms cannot be created or destroyed in a chemical reaction

B) molecules cannot be created or destroyed in a chemical reaction

C) compounds cannot be created or destroyed in a chemical reaction

D) heat cannot be created or destroyed in a chemical reaction

2) Identify the correct classification for the reaction 2 PbSO4 → 2 PbSO3 + O2

A) Combination

B) Decomposition

C) Single Replacement

D) Double Replacement

E) None of the choices are correct.

3) Identify the correct classification for the reaction H2O + SO3 →  H2SO4

A) Combination

B) Decomposition

C) Single Replacement

D) Double Replacement

E) None of the choices are correct.

4) Which reaction is a double displacement reaction?

A) 3 Mg + Fe2O3 → 2 Fe + 3 MgO

B) 2 KBr + Cl2 → 2 KCl + Br2

C) 2 H2 + O2 → 2 H2O

D) 3 Ca(OH)2 + Al2(SO4)3  → 3 CaSO4 + 2 Al(OH)3

5) Identify the correct product that would complete the following double displacement reaction:

NaOH + HBr →  ___ + H2O

A) HBr

B) NaH

C) NaBr

D) OBr2

E) None of the choices are correct.

6) The Greek letter delta (Δ) may be written over the reaction arrow in a chemical equation to indicate that ________.

A) heat is generated when the reaction occurs

B) a catalyst is needed for the reaction to occur

C) water is needed for the reaction to occur

D) heat is needed for the reaction to occur

7) Which chemical equation is properly balanced?

A) SO2 + O2 + H2O → H2SO4

B) 2 SO2 + O2 + 2 H2O → 2 H2SO4

C) SO2 + O2 + 4 H2O → 2 H2SO4

D) 4 SO2 + O2 + 4 H2O → 4 H2SO4

8) In the chemical equation 2 Co(NO3)3 + 3 (NH4)2S → Co2S3 + 6 NH4NO3 , how many nitrogen atoms are on each side of the equation?

A) 2

B) 3

C) 6

D) 12

E) 16

9) Write a balanced chemical equation for the reaction of acetone (C3H6O) with oxygen (O2) to form carbon dioxide (CO2) and water (H2O).

A) C3H6O + O2 → CO2 + H2O

B) C3H6O + 4 O2 → 3 CO2 + 3 H2O

C) 3 CO2 + 3 H2O → C3H6O + 4 O2

D) 6 C3H6O + 8 O2 → 6 CO2 + 6 H2O

10) How many carbon atoms are in 3.85 mol of carbon?

A) 3.85 carbon atoms

B) 23.2 carbon atoms

C) 6.02 × 1023 carbon atoms

D) 2.32 × 1024 carbon atoms

E) 6.40 × 10–24 carbon atoms

11) How many iron atoms are in 0.32 mol of Fe2O3?

A) 3.9 × 1023 iron atoms

B) 3.9 iron atoms

C) 6.02 × 1023 iron atoms

D) 1.9 × 1023 iron atoms

E) 1.1 × 10–24 iron atoms

12) How many moles of chloroethylene (C2H3Cl) contain 5.47 × 1026 molecules?

A) 3.29 × 1050 mol of C2H3Cl

B) 5.47 × 1026 mol of C2H3Cl

C) 909 mol of C2H3Cl

D) 5450 mol of C2H3Cl

13) What is the formula weight of KCl?

A) 74.55 amu

B) 66.42 amu

C) 36.00 amu

D) 1386 amu

14) What is the formula weight of Co(NO3)3?

A) 88.94 amu

B) 244.96 amu

C) 216.94 amu

D) 148.96 amu

E) 196.96 amu

15) What is the mass of 3.81 mol of PH3?

A) 34.0 g

B) 3.81 g

C) 8.92 g

D) 130. g

E) 0.112 g

16) How many moles of carbon dioxide are in 211 g of carbon dioxide?

A) 929 mol of CO2

B) 4.79 mol of CO2

C) 167 mol of CO2

D) 0.209 mol of CO2

17) Aspartic acid is an amino acid used to synthesize proteins. What is the molar mass of aspartic acid shown below?

A) 121.09 g/mol

B) 133.11 g/mol

C) 117.0 g/mol

D) 126.04 g/mol

E) 132.09 g/mol

18) Which sample contains the largest number of molecules?

A) 100 g of CO2

B) 100 g of CH4

C) 100 g of CBr4

D) 100 g of CHBr3

19) Complete the following table using the given balanced equation and the initial quantities of reactants.

Equation: N2(g) +  2 O2(g)  →  2 NO2(g)

A) 10 molecules formed

B) 5 molecules formed

C) 12 molecules formed

D) 15 molecules formed

20) Complete the following table using the given balanced equation and the initial quantities of reactants.

Equation: S8  + 12 O2  →  8 SO3

A) 16 molecules formed

B) 8 molecules formed

C) 32 molecules formed

D) 1 molecule formed

21) The molecules A and B react according to the following chemical equation: A + B → C. Identify the limiting reactant under the reaction conditions shown in the molecular art below.

A = large grey circles

B = small black circles

A) A is the limiting reactant

B) B is the limiting reactant

C) Both A and B are the limiting reactants

D) Neither A nor B are the limiting reactants

22) The molecules A and B react according to the following chemical equation: A + 2B → C. Identify the limiting reactant under the reaction conditions shown in the molecular art below.

A = large white circles

B = small grey circles

A) A is the limiting reactant

B) B is the limiting reactant

C) Both A and B are the limiting reactants

D) Neither A nor B are the limiting reactants

23) How many moles of sulfur trioxide are formed from 3 moles of sulfur dioxide using the given balanced equation?

2 SO2 + O2 → 2 SO3

A) 1 mol of SO3

B) 2 mol of SO3

C) 3 mol of SO3

D) 5 mol of SO3

E) 6 mol of SO3

24) How many moles of sulfur trioxide are formed from 3 moles of oxygen using the given balanced equation?

2 SO2 + O2 → 2 SO3

A) 1 mol of SO3

B) 2 mol of SO3

C) 3 mol of SO3

D) 5 mol of SO3

E) 6 mol of SO3

25) Consider the reaction: 2 Al(OH)3 + 3 H2SO4 → Al2(SO4)3 + 6 H2O. How many grams of Al2(SO4)3 are generated when 152 g of H2SO4 reacts?

A) 530. g of Al2(SO4)3

B) 1590 g of Al2(SO4)3

C) 177 g of Al2(SO4)3

D) 43.6 g of Al2(SO4)3

E) 131 g of Al2(SO4)3

26) A balanced chemical equation tells the number of ________ of each reactant that combine and the number of ________ of each product formed.

A) grams; grams

B) grams; moles

C) moles; grams

D) moles; moles

27) Suppose the theoretical yield in a reaction is 10.5 g and the percent yield is 75.5%. What is the actual yield of product obtained?

A) 793 g

B) 7.93 g

C) 13.9 g

D) 0.139 g

28) Consider the oxidation of sodium metal to sodium oxide described by the balanced equation:

4 Na + O2 → 2 Na2O. What is the theoretical yield of Na2O in grams from 9.0 mol of O2?

A) 11 g of Na2O

B) 410 g of Na2O

C) 1,100 g of Na2O

D) 280 g of Na2O

E) 560 g of Na2O

29) Consider the oxidation of sodium metal to sodium oxide described by the balanced equation:

4 Na + O2 → 2 Na2O. If 2.55 mol of sodium reacts, and 75.0 g of Na2O is produced, what is the percent yield?

A) 94.9% yield

B) 34.0% yield

C) 47.5% yield

D) 190.% yield

30) If a synthesis has four steps and each step has a 75% yield (0.75 written as a decimal), what is the overall percent yield?

A) 75%

B) 19%

C) 56%

D) 32%

E) 42%

31) Potassium metal (K) reacts violently when added to water according to the balanced equation:

2 K(s) + 2 H2O(l) → 2 KOH(aq) + H2(g). How many moles of H2O are needed to react completely with 7.54 mol of K?

A) 2 mol of H2O

B) 7.54 mol of H2O

C) 15.1 mol of H2O

D) 3.77 mol of H2O

32) Tin (II) fluoride can be made by the following reaction: Sn(s) + 2 HF(g) → SnF2(s) + H2(g). What is the maximum amount of SnF2 that can be produced when 0.480 moles of Sn are mixed with 0.720 moles of HF?

A) 0.360 moles of SnF2

B) 0.480 moles of SnF2

C) 0.600 moles of SnF2

D) 0.720 moles of SnF2

E) 1.20 moles of SnF2

33) Identify the species that is oxidized and the species that is reduced in the reaction:

2 I– + Cl2 → 2 Cl– + I2.

A) I– is oxidized and Cl2 is reduced.

B) Cl2 is oxidized and I– is reduced.

C) I2 is oxidized and Cl– is reduced.

D) Cl2 is oxidized and Cl– is reduced.

E) I2 is oxidized and I– is reduced.

34) What are the two half reactions that show how many electrons are gained or lost by each species in the reaction:

Ni2+(aq) + Mg(s) → Ni(s) + Mg2+(aq)?

A) Ni2+(aq) + e– → Ni(s) and Mg(s) → Mg2+(aq) + e–

B) Ni2+(aq) + 2 e– → Ni(s) and Mg(s) → Mg2+(aq) + 2 e–

C) Ni2+(aq) → Ni(s) + 2 e– and Mg(s) + 2 e– → Mg2+(aq)

D) Ni2+(aq) → Ni(s) + e– and Mg(s) + e– → Mg2+(aq)

E) Ni2+(aq) + 2 e– → Ni(s) and Mg(s) + 2 e– → Mg2+(aq)

35) Which quantity has the greatest mass?

A) 2.0 mol of Na

B) 2.0 mol of Na2O

C) 2.0 mol of NaCl

D) 2.0 mol of O2

E) All of these quantities have the same mass.

36) How many moles of sodium chloride (table salt, NaCl, molar mass 58.44 g/mol) are contained in a 1.00 lb box of table salt?

A) 26,500 mol of NaCl

B) 4.68 × 1024 mol of NaCl

C) 58.44 mol NaCl

D) 7.77 mol of NaCl

E) 0.129 mol of NaCl

37) Consider the mixture of Cl2 and F2 in a closed container as illustrated below. What will the contents of the container look like if the molecules undergo the reaction:

Cl2(g) + 3 F2(g) → 2 ClF3(g)?

A)

B)

C)

D)

38) In the balanced redox reaction: 2 Cu(s) + S(s) → Cu2S(s), how many electrons are gained or lost by each copper atom?

A) Each copper atom gains two (2) electrons

B) Each copper atom gains one (1) electron

C) Each copper atom loses one (1) electron

D) Each copper atom loses two (2) electrons

39) In the balanced redox reaction: 2 C2H6(g) + 7 O2(g) → 4 CO2(g) + 6 H2O(g), which species is oxidized?

A) C2H6(g)

B) O2(g)

C) CO2(g)

D) H2O(g)

40) In the balanced redox reaction: 2 C2H6(g) + 7 O2(g) → 4 CO2(g) + 6 H2O(g), which species is reduced?

A) C2H6(g)

B) O2(g)

C) CO2(g)

D) H2O(g)

41) How many grams of oxygen gas are required to completely react with 77.28 g of ethane (C2H6) in the balanced redox reaction: 2 C2H6(g) + 7 O2(g) → 4 CO2(g) + 6 H2O(g)?

A) 77.28 g of O2(g)

B) 23.50 g of O2(g)

C) 143.9 g of O2(g)

D) 8.995 g of O2(g)

E) 287.8 g of O2(g)

42) How many carbon atoms are in 77.28 g of ethane (C2H6)?

A) 2.570 carbon atoms

B) 5.140 carbon atoms

C) 3.094 × 1024 carbon atoms

D) 1.548 × 1024 carbon atoms

E) 1.238 × 1025 carbon atoms

43) What is the molar mass of the compound show below? 

A) 90.13 amu

B) 90.13 g/mol

C) 93.13 amu

D) 93.13 g/mol

E) 91.14 g/mol

44) What is the mass of 3.4 × 1020 molecules of ethanol (C2H6O) expressed in milligrams?

A) 0.026 mg of ethanol

B) 26,000 mg of ethanol

C) 0.012 mg of ethanol

D) 26 mg of ethanol

45) The chemical equation: KClO3(s) → KCl(s) + O2(g) is not balanced. Balance this equation, then select the statement that best describes the balanced equation.

A) The balanced equation will have six atoms of oxygen on each side of the equation.

B) The balanced equation will have one atom of chlorine on each side of the equation.

C) The balanced equation will have an O3 on the product side of the equation.

D) The balanced equation will have a coefficient of 1 in front of KCl.

46) Sodium fluoride can be produced from the reaction between sodium metal and fluorine gas. Which of the following represents the balanced chemical equation for this reaction?

A) 2 Na(s) + F2(g) → 2 NaF(s)

B) Na+(s) + F–(g) → NaF(s)

C) Na(s) + F2(g) → NaF2(s)

D) 2 Na(s) + F2(g) → Na2F2(s)

47) The conversion factor shown below was obtained from the balanced chemical equation: 4 KO2(s) + 2 CO2(g) → 2 K2CO3(s) + 3 O2(g). This conversion factor would be used to calculate which of the following?

A) The amount of KO2 required to react with a certain amount of O2

B) The amount of O2 that can react with a certain amount of KO2

C) The amount of O2 that can be produced from a certain amount of KO2

D) The amount of KO2 that is required to produce a certain amount of O2

48) Blimps are essentially very large helium filled balloons. If a blimp contains 536 kg of helium, how many helium atoms are present inside the blimp?

A) 134,000 He atoms

B) 8.9 x 10-19 He atoms

C) 8.06 x 1028 He atoms

D) 3.23 x 1026 He atoms

49) Beaker A contains 1 mole of iron atoms, and Beaker B contains 1 mole of lead atoms. Which statement concerning these two samples is known with certainty? 

A) Beakers A and B contain samples with the same molar mass.

B) Beakers A and B contain an equal number of atoms.

C) Beakers A and B contain an equal volume of atoms.

D) Beakers A and B contain equal masses of atoms.

50) Assume that the mixture of substances in Figure 1 undergoes a chemical reaction. Which diagram represents a product mixture that is consistent with the Law of Conservation of Mass?

A)

B)

C)

D) It is impossible to predict based on the information given.

51) A student runs the reaction: LiOH + CO2 → LiHCO3. The reaction consumes 45.0 g LiOH and produces 72.8 g of LiHCO3. Which of the statements concerning this reaction is true?

A) The actual yield of the product is 72.8 g LiHCO3.

B) The theoretical yield of the product is 72.8 g LiHCO3.

C) The theoretical yield of the product is 117.8 g LiHCO3.

D) The percent yield of the reaction is 61.8%.

52) The subscripts in chemical formulas are changed in order to balance a chemical equation.

53) A chemical equation is balanced by adding coefficients in front of some formulas so that the number of atoms of each element is equal on both sides of the equation.

54) A mole of copper atoms has more atoms than a mole of lead atoms.

55) One mole of oxygen molecules contains more atoms than one mole of lead atoms.

56) The molar mass of CaCO3 is greater than the molar mass of Ca(NO3)2.

57) The actual yield is the amount of product expected from a given amount of reactant based on the coefficients in the balanced chemical equation.

58) In calculating the percent yield, both the actual yield and theoretical yield must be in units of grams.

59) Oxidation is the gain of electrons by an atom.

60) All chemical reactions convert one substance into another.

61) In the reaction: Ni2+(aq) + Mg(s) → Ni(s) + Mg2+(aq), the oxidizing agent is Ni2+(aq).

62) In the reaction: Ni2+(aq) + Mg(s) → Ni(s) + Mg2+(aq), the species that undergoes reduction is Mg(s).

63) Combustion reactions are redox reactions.

64) The balanced reaction: 4 NO2 + O2 + 2 H2O → 4 HNO3 states that four moles of nitrogen dioxide react with each mole of oxygen.

65) The balanced reaction: 4 NO2 + O2 + 2 H2O → 4 HNO3 states that four grams of nitrogen dioxide reacts with each gram of oxygen.

66) The balanced reaction: 4 Fe(s) + 3 O2(g) → 2 Fe2O3(s) is an oxidation-reduction reaction.

67) A mole is a quantity that contains 6.02 × 10–23 atoms, molecules, or ions.

68) The formula weight of a compound is the sum of the atomic weights of all the atoms in a compound, reported in atomic mass units.

69) When the mass of a substance produced in a reaction must be calculated, first its number of moles is determined using mole ratios, and then Avogadro's number is used to convert moles to grams.

70) The actual yield of a product in a chemical reaction should not exceed its theoretical yield.

71) In redox reactions, metals tend to undergo oxidation.

72) The electric current generated in batteries used for portable electronic devices and pacemakers results from redox reactions.

73) The reaction: Mg(s) + 2 HBr(aq) → MgBr2(s) + H2(g) is an oxidation-reduction reaction.

74) Consider the balanced reaction: 4 NO2 + O2 + 2 H2O → 4 HNO3. If 100. g of NO2 is placed in a reaction vessel the theoretical yield of nitric acid (HNO3) collected will be 137 g.

75) In a chemical reaction, the actual yield of a product may be reduced by side reactions.

76) 2 Co(NO3)3(aq) + 3 (NH4)2S(aq) → Co2S3(s) + 3 NH4NO3(aq) is a properly balanced chemical equation.

77) To determine the overall percent yield in a synthesis that has more than one step, subtract the percent yield for each step from 100% yield.

78) Consider the balanced reaction: 2 A + B → C, where the molar mass of B is less than the molar mass of A. It requires a smaller mass of A to completely react with given mass of B.

79) In the reaction: Ni2+(aq) + Mg(s) → Ni(s) + Mg2+(aq), two electrons are transferred from Ni2 to Mg.

80) A 100-g sample of the compound below contains greater than one mole of molecules. 

81) A 100-g sample of the compound below contains less than 6.02 × 1023 molecules.

82) One term in a balanced chemical equation contains the coefficient 4 in front of the formula Mg3(PO4)2. This term represents that there are 12 Mg atoms, 4 P atoms, and 16 O atoms in this term.

83) To multiply two numbers in scientific notation, multiply the coefficients together and multiply the exponents in the powers of 10.

84) The molar mass of dibromomethane (CH2Br2) is larger than the molar mass of dichloromethane (CH2Cl2).

85) A 200-mg ibuprofen (C13H18O2) tablet contains greater than one mole of ibuprofen molecules.

86) Consider the unbalanced chemical equation: NH3 + O2 → NO + H2O. It requires 55.4 g of NH3 to completely react with 156 g of O2.

87) The mass of one ethanol (C2H6O) molecule is 7.65 × 10–23 grams.

88) A chemical change alters the chemical composition of a substance, and therefore a new substance is produced.

89) A chemical equation is an expression that uses chemical formulas and other symbols to illustrate what ________ constitute the starting materials in a reaction and what ________ are formed.

90) When calculating the number of moles of calcium hydroxide formed from each mole of sodium hydroxide in the balanced reaction: CaCl2 + 2 NaOH ® Ca(OH)2 + 2 NaCl, the necessary conversion factor is  ________.

91) A redox reaction involves the transfer of ________ from one element to another.

92) A compound that gains electrons in a redox reaction while causing another compound to be oxidized is called a(n) ________ agent.

93) _____ results in the loss of oxygen atoms or the gain of hydrogen atoms.

94) In a redox reaction, the ________ agent is the substance that gets oxidized.

95) In a two-step synthesis where the first reaction has a 55% yield and the second reaction has a 24% yield, the overall percent yield of the reaction is _____% yield.

96) In the balanced reaction: 2 I– + Cl2 → 2 Cl– + I2, ________ is the reducing agent and ________ is the oxidizing agent.

97) Aluminum metal and oxygen gas are obtained when aluminum oxide is heated at high temperature. The reactant(s) in this chemical reaction is(are) ________.

98) The combustion of hexane (C6H14), a component of gasoline, is represented by the balanced chemical equation: 2 C6H14(l) + 19 O2(g) → 12 CO2(g) + 14 H2O(g). If 1.0 mole of hexane undergoes combustion, ________ moles of O2 are required.