Test Bank Chapter 4 Calculations, Chemical Changes, and the

General, Organic, and Biochemistry, 10e (Denniston)

Chapter 4 Calculations, Chemical Changes, and the Chemical Equation

1) One mole of any substance contains Avogadro's number of particles of that substance. What is the numerical value of Avogadro's number?

A) 6.022 ×10−23

B) 1.00 ×10−14

C) 12.01

D) 1.661 ×10−24

E) 6.022 × 1023

2) What is the mass of 4.00 moles of helium, the gas commonly used to fill party balloons and lighter-than-air ships?

A) 4 amu

B) 4.00 g

C) 8.00 g

D) 16.0 g

E) 2.41 × 1024 g

3) A sample of aluminum contains 2.91 × 1022 atoms of aluminum. What is the mass of this sample? [Molar mass: Al, 26.98 g/mol]

A) 0.767 g

B) 1.30 g

C) 558 g

D) 1.08 × 1021 g

E) 7.85 × 1023g

4) What is the general term for the process in which one or more electrons are transferred from one reactant to another?

A) oxidation-reduction

B) neutralization

C) condensation

D) Lewis base

E) decomposition

5) Which notation properly indicates how two molecules of diatomic oxygen would be represented in a chemical equation?

A) (O2)2

B) O4

C) 2O2

D) O2O2

E) All of the choices are correct.

6) Which has the greatest mass, one atom of carbon, one atom of hydrogen, or one atom of lithium?

A) one atom of carbon   

B) one atom of hydrogen

C) one atom of lithium

D) All three atoms have the same mass.

E) It is impossible to determine.

7) What is the mass of one mole of diatomic hydrogen, H2?

A) 1.01 amu

B) 2.02 amu

C) 1.01 g

D) 2.02 g

E) 6.022 × 1023 g

8) How many molecules of water are present in a 5.65 mole sample of water?

A) 4.00 × 1024 molecules

B) 1.07 × 1023 molecules

C) 3.40 × 1024 molecules

D) 9.39 × 10−24 molecules

E) 4.00 × 1025 molecules

9) The mass of one atom of oxygen is 16.00 amu. What is the mass of one mole of elemental oxygen (O2)?

A) 32.00 amu

B) 32.00 g

C) 9.64 × 1024 g

D) 1.93 × 1025 g

E) 1.88 × 1022 g

10) Which statement best describes the Law of Conservation of Mass?

A) The masses of the reactants in a chemical reaction are always equal.

B) The mass of the product formed in a chemical reaction is determined by the limiting reactant.

C) The mass of the product formed in a chemical reaction is equal to the mass of the reactant in the smallest amount.

D) Matter is neither gained nor lost in a chemical reaction.

E) When two or more products are formed in a chemical reaction, their masses will always be equal.

11) Which symbol, often found in chemical equations, indicates that a substance is dissolved in water?

A) (w)

B) (l)

C) (aq)

D) (d)

E) ∆

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

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

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

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

D) Beakers A and B contain samples with the same density.

E) None of these are correct.

13) The chemical equation below is unbalanced. What is the coefficient of water when the equation is balanced? Mg(OH)2(s) + HCl(g) → MgCl2(s) + H2O(l)

A) 1

B) 2

C) 3

D) 4

E) No coefficient would be shown.

14) Aluminum metal and oxygen gas are produced when aluminum oxide is heated at high temperature. Which statement concerning this chemical change is true?

A) Aluminum oxide is the product in this reaction.

B) This reaction is a neutralization reaction.

C) Aluminum and oxygen are the reactants in this reaction.

D) This reaction is a decomposition reaction.

E) The chemical equation for this reaction is: AlO2(s) → Al(s) + O2(g).

15) The unbalanced equation for the combustion of octane, a component of gasoline, is shown below. What would be the coefficient of carbon dioxide once the equation is balanced?

C8H18(l) + O2(g) → CO2(g) + H2O(l)

A) 8

B) 25

C) 16

D) 18

E) No coefficient would be shown.

16) The chemical equation below is not balanced. Balance the equation, then determine which statement concerning the balanced equation is TRUE.

KClO3(s) → KCl(s) + O2(g)

A) The balanced equation will have an equal number of moles of reactants and products.

B) The balanced equation will have three atoms of oxygen on each side.

C) The balanced equation will have one atom of potassium on each side.

D) The balanced equation will have two atoms of chlorine on each side.

E) The balanced equation will contain a substance whose coefficient is 1.

17) Consider the chemical equation shown below. How many moles of oxygen gas are needed to react with hydrogen to form one mole of water? 2H2(g) + O2(g) → 2H2O(l)

A) 0.5 mol

B) 1 mol

C) 3 mol

D) 4 mol

E) 5 mol

18) Hydrogen fluoride will react with glass (silicon dioxide, SiO2) according to the equation below. What mass of HF is required to react completely with 16.0 g of glass?[Molar masses: Si, 28.09 g/mol; F, 19.00 g/mol; H, 1.01 g/mol; O, 16.00 g/mol]

4HF(g) + SiO2(s) → SiF4(g) + 2H2O(g)

A) 5.33 g

B) 21.3 g

C) 64.0 g

D) 80.0 g

E) 320 g

19) Glucose (C6H12O6) is an important energy-rich compound produced by photosynthesis according to the equation below. What mass of glucose can be produced from 2.61 mol of CO2 and the necessary water? [Molar masses: C, 12.01 g/mol; H, 1.01 g/mol; O, 16.00 g/mol]

6CO2(g) + 6H2O(l) → C6H12O6(l) + 6O2(g)

A) 0.0128 g

B) 0.0869 g

C) 69.0 g

D) 78.4 g

E) 414 g

20) Upon mixing a clear colorless BaCl2 solution with a clear, colorless Na2SO4 solution according to the reaction below, a student observes a white cloudiness form. What is responsible for the cloudiness that is observed?

BaCl2(aq) + Na2SO4(aq) → BaSO4(s) + 2NaCl(aq)

A) NaCl

B) BaSO4

C) BaCl2

D) Na2SO4

E) It is impossible to tell without doing the reaction oneself.

21) The fluoride rinse in dental offices usually contains sodium fluoride. Sodium fluoride can be prepared from the reaction between sodium metal and fluorine gas. Which of the following properly represents the balanced chemical equation for this reaction?

A) Na(s) + F2(g) → NaF2(s)

B) Na(s) + F(g) → NaF(s)

C) 7Na(s) + F(g) → Na7F(s)

D) 2Na(s) + F2(g) → 2Na2F(s)

E) 2Na(s) + F2(g) → 2NaF(s)

22) How is the reaction shown below best classified? Ca(s) + 2HCl(aq) → CaCl2(g) + H2(g)

A) decomposition

B) combination

C) single-replacement

D) double-replacement

E) precipitation

23) How is the reaction shown below best classified?

2NaCl(s) + F2(g) → 2NaF(s) + Cl2(g)

A) decomposition

B) combination

C) single-replacement

D) double-replacement

E) precipitation

24) How is the reaction shown below best classified? 2HgO(s) → 2Hg(l) + O2(g)

A) decomposition

B) combination

C) single-replacement

D) double-replacement

E) acid-base reaction

25) What is the mass of a 0.150 mole sample of sulfur?

A) 5.17 g

B) 4.68 g

C) 214 g

D) 0.208 g

E) 4.81 g

26) A sample of sulfur contains 1.81 × 1024 atoms of sulfur. How many moles of sulfur does this represent?

A) 1.81 mol

B) 3.01 mol

C) 0.333 mol

D) 1.09 mol

E) 1.77 mol

27) Diamond is a pure form of the element carbon. If a 2 carat diamond has a mass of 0.396 g, how many carbon atoms are contained in this diamond?

A) 3.97 × 1022 atoms

B) 6.58 × 10−25 atoms

C) 1.99 × 1023 atoms

D) 1.99 × 1022 atoms

E) 2.38 × 1023 atoms

28) Cisplatin is a chlorine-containing chemotherapy agent with the formula Pt(NH3)2Cl2. What is the mass of one mole of cisplatin?

A) 283.02 g/mol

B) 286.05 g/mol

C) 300.06 g/mol

D) 488.91 g/mol

E) 492.37 g/mol

29) Dinitrogen monoxide, or laughing gas (N2O), is used as a dental anesthetic and as an aerosol propellant. How many molecules of N2O are present in a 12.6 g sample of the compound?

A) 1.72 × 1023 molecules

B) 1.289 molecules

C) 3.34 × 1026 molecules

D) 7.59 × 1024 molecules

E) 5.14 × 1023 molecules

30) When the equation below is balanced with the lowest possible whole number coefficients, what is the sum of the coefficients? Ca(s) + HCl(g) → CaCl2(s) + H2(g)

A) 2

B) 4

C) 5

D) 8

E) 10

31) Lithium oxide can be produced by the reaction shown below. If a manufacturing company wants to make 25.0 g of Li2O, what mass of Li is necessary? [Molar masses: Li, 6.94 g/mol; O, 16.00 g/mol]

4Li(s) + O2(g) → 2Li2O(s)

A) 0.0861 g Li

B) 2.903 g Li

C) 11.6 g Li

D) 12.5 g Li

E) 23.2 g Li

32) What mass of sodium hydroxide is necessary to react with a solution containing 73.00 g HCl, according to the chemical equation below? [Molar masses: NaOH, 39.99 g/mol; HCl, 36.45 g/mol]

NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)

A) 80.09 g

B) 66.54 g

C) 39.99 g

D) 1.850 g

E) 7.445 g

33) Iron reacts with oxygen to form iron(III) oxide according to the chemical equation below. What is the theoretical yield of product when 5.00 grams of Fe react with excess O2? [Molar masses: Fe, 55.85 g/mol; O, 16.00g/mol]

4Fe(s) + 3O2(g) → 2Fe2O3(s)

A) 13.1 g

B) 6.53 g

C) 7.15 g

D) 2.50 g

E) 70.5 g

34) Magnesium hydroxide, Mg(OH)2, as "Milk of Magnesia" can be used to neutralize excess stomach acid, represented by HCl(aq) according to the chemical equation below.

Mg(OH)2(s) + 2HCl(aq) → MgCl2(aq) + 2H2O(l)

When 5.00 g of HCl are combined with an excess of Mg(OH)2, what mass of MgCl2 can be produced? [Molar masses: H, 1.01 g/mol; O, 16.00 g/mol; Mg, 24.31 g/mol; Cl, 35.45 g/mol]

A) 13.1 g

B) 6.53 g

C) 0.957 g

D) 2.50 g

E) 70.5 g

35) To convert a given number of moles into the number of atoms, one would multiply by which of the following factors?

A) 6.022 × 1023 atoms/1 mol

B) 1 mol/6.022 × 1023 atoms

C) 1.66 × 10-24 atoms/1 mol

D) 1 mol/1.66 × 10-24 atoms

E) molar mass

36) The average mass of one atom of copper is 63.55 amu. What is the mass of Avogadro's number of copper atoms?

A) 3.827 × 1025 amu

B) 63.55 g

C) 3.827 × 1025 g

D) 63.55 atoms

E) 63.55 formula units

37) What is the mass of one mole of carbon atoms?

A) 6.022 g

B) 12.01 g

C) 7.232 g

D) 6.022 × 1023 g

E) 7.232 × 1024 g

38) What is the mass of 3.01 mol of sulfur atoms?

A) 1.81 × 1024 g

B) 32.06 g

C) 3.01 g

D) 0.150 g

E) 96.5 g

39) How many moles of Au atoms are present in one ounce of pure gold? [1 oz = 28.4 g]

A) 1.97 × 102 mol

B) 6.94 mol

C) 0.144 mol

D) 0.0721 mol

E) 5.08 × 10-3 mol

40) How many atoms of sulfur are present in a 155 g sample of sulfur? [Molar mass: S, 32.06 g/mol]

A) 2.91 × 1024 atoms

B) 6.02 × 1023 atoms

C) 3.01 × 1023 atoms

D) 2.91 × 1023 atoms

E) 2.01 × 1023 atoms

41) How many iron atoms are present in 0.552 mol of iron?

A) 2.798 × 1024

B) 6.02 × 1023

C) 27.98

D) 3.32 × 1023

E) 55.85

42) What is the formula mass of carbon dioxide? [Atomic masses: C, 12.01 amu; O, 16.00 amu]

A) 28.01 amu

B) 28.01 g

C) 44.01 amu

D) 44.01 g

E) 44.01 mol

43) Aspirin is the common name for acetyl salicylic acid, C9H8O4. One tablet contains 0.325 g of aspirin. How many moles of aspirin is this?

A) 1.80 × 10-6 mol

B) 1.80 × 10-3 mol

C) 0.554 mol

D) 554 mol

E) 1.96 × 1023 mol

44) What is the mass of a 0.0200 mol sample of nicotine? [Formula mass: nicotine, 162.2 amu]

A) 1.23 × 10-4 g

B) 0.308 g

C) 3.24 g

D) 32.4 g

E) 8.11 × 103 g

45) How many molecules are present in a 0.0200 mol sample of nicotine?

A) 0.0400 molecules

B) 1.20 × 1022 molecules

C) 2.41 × 1022 molecules

D) 6.02 × 1023 molecules

E) 1.20 × 1023 molecules

46) How many aspirin molecules are present in a 0.325 g sample of aspirin? [Molar mass: aspirin, 180.2 g/mol]

A) 1.09 × 1021 molecules

B) 1.80 × 10−3 molecules

C) 1.96 × 1023 molecules

D) 3.91 × 1023 molecules

E) 58.57 molecules

47) The chemical equation below is not balanced. What is the coefficient of iron when the equation is balanced with smallest whole number coefficients?

Fe(s) + O2(g) → Fe2O3(s)

A) 1

B) 2

C) 3

D) 4

E) 8

48) Incomplete combustion occurs when there is insufficient oxygen to react with a compound. The suffocating gas carbon monoxide is a product of incomplete combustion. How many moles of oxygen gas are required for the complete combustion of 11.0 moles of C6H14, a component of gasoline?

C6H14(l) + 19O2(g) → 12CO2(g) + 14H2O(l)

A) 1.16 mol O2

B) 28.0 mol O2

C) 105 mol O2

D) 209 mol O2

E) 418 mol O2

49) Which of the choices is the correctly balanced form of the following equation?

C6H14(l) + O2(g) → CO2(g) + H2O(l)

A) C6H14(l) + 13O2(g) → 6CO2(g) + 7H2O(l)

B) C6H14(l) + 19O(g) → 6CO2(g) + 7H2O(l)

C) C6H14(l) + 19O2(g) → 6CO2(g) + 7H2O(l)

D) 2C6H14(l) + 19O2(g) → 12CO2(g) + 14H2O(l)

E) C12H28(l) + 38O(g) → 12CO2(g) + 14H2O(l)

50) How many moles of hydrogen gas are needed to react with oxygen to form one mole of water?

2H2(g) + O2(g) → 2H2O(l)

A) 0.5 mol

B) 1 mol

C) 2 mol

D) 4 mol

E) 6 mol

51) Methanol (CH3OH) is the fuel used by racecars in the Indianapolis 500. It burns in the engine according to the equation below. How many moles of oxygen gas are necessary to react completely with 425 moles of methanol?

2CH3OH(l) + 3O2(g) → 2CO2(g) + 4H2O(g)

A) 3 mol

B) 255 mol

C) 283 mol

D) 638 mol

E) 1275 mol

52) Methanol (CH3OH) is the fuel used by racecars in the Indianapolis 500. It burns in the engine according to the equation below. How many moles of oxygen gas are necessary to react completely with 12.5 L of methanol? [Density: CH3OH, 0.7910g/mL; Molar mass: CH3OH, 32.05 g/mol]

2CH3OH(l) + 3O2(g) → 2CO2(g) + 4H2O(g)

A) 0.462 mol

B) 2.16 mol

C) 463 mol

D) 740 mol

E) 1850 mol

53) Consider the hypothetical reaction: 3A2 + 2B → C + 2D If 6.0 moles of A are mixed with 2.0 moles of B, what is the maximum amount of C that can be formed?

A) 1.0 mol

B) 2.0 mol

C) 5.0 mol

D) 6.0 mol

E) 8.0 mol

54) Classify the following reaction: Ce4+(aq) + Fe2+(aq) → Ce3+(aq) + Fe3+(aq)

A) precipitation

B) acid - base

C) oxidation - reduction

D) decomposition

E) neutralization

55) Classify the following reaction: H2SO4(aq) + 2KOH(aq) → K2SO4(aq) + 2H2O(aq)

A) precipitation

B) acid - base

C) oxidation - reduction

D) decomposition

E) combustion

56) When solutions of sodium sulfide and copper(II) sulfate are mixed, a precipitate of copper(II) sulfide is formed. What is the net ionic equation for this reaction?

A) Na2S(aq) + CuSO4(aq) → Na2SO4(aq) + CuS(s)

B) Na2S(aq) + CuSO4(aq) → CuS(s)

C) Cu2+(aq) + S2-(aq) → Cu(s) + S(s)

D) Cu2+(aq) + S2-(aq) → CuS(s)

E) 2Na+(aq) + S2-(aq) + Cu2+(aq) + SO42-(aq) → 2Na+(aq) + SO42-(aq)

57) Consider the following precipitation reaction. Which of the following correctly identifies the spectator ions in this reaction? Na2S(aq) + CuSO4(aq) → Na2SO4(aq) + CuS(s)

A) Na2+, S2-, Cu2+, and SO42-

B) Na+, S2-, Cu2+, and SO42-

C) Na+ and SO42-

D) Cu2+ and S2-

E) There are no spectator ions present.

58) Choose the best classification of the reaction represented by the following equation: 2KClO3(s) → 2KCl(s) + 3O2(g)

A) decomposition

B)  combination

C) single-replacement

D) double-replacement

E) None of the choices are correct.

59) Choose the best classification of the reaction represented by the following equation: Na2SO4(aq) + Ba(OH)2(aq) → BaSO4(s) + 2NaOH(aq)

A) decomposition

B) combination

C) single-replacement

D) double-replacement

E) None of the choices are correct.

60) Prozac, a drug prescribed to treat depression, has the formula C17H18F3NO. If a patient was administered 15.0 mg of Prozac, how many moles of Prozac did he receive? [Molar mass: Prozac, 309.36 g/mol]

A) 4.85 × 10−5 mol

B) 48.5 mol

C) 20.6 mol

D) 4640 mol

E) 2.92 × 1019 mol

61) Choose the best classification of the reaction represented by the following equation: HBr(aq) + KOH(aq) → KBr(aq) + H2O(l)

A) oxidation-reduction

B) combination

C) precipitation

D) decomposition

E) acid-base

62) Choose the best classification of the reaction represented by the following equation: 2Fe3+(aq) + Fe(s) → 3Fe2+(aq)

A) neutralization

B) decomposition

C) acid-base

D) oxidation-reduction

E) precipitation

63) Choose the best classification of the reaction represented by the following equation: Pb(NO3)2(aq) + CaCl2(aq) → PbCl2(s) + Ca(NO3)2(aq)

A) neutralization

B) acid-base

C) decomposition

D) precipitation

E) oxidation-reduction

64) Choose the best classification of the reaction represented by the following equation: MgO(s) + CO2(g) → MgCO3(s)

A) single-replacement

B) double-replacement

C) combination

D) decomposition

E) precipitation

65) Consider the hypothetical reaction: 3A2 + 2B → C + 2D

When 25 g of reactant A and 34 g of reactant B are combined, the theoretical yield of product C is 31 g. If the actual yield of product C is 19 g, what is the percent yield of C?

A) 53%

B) 61%

C) 76%

D) 56%

E) 85%

66) Choose the best classification of the reaction represented by the following equation: BaCl2(aq) + K2SO4(aq) → BaSO4(s) + 2KCl(aq)

A) single-replacement

B) double-replacement

C) combination

D) decomposition

E) oxidation-reduction

67) What is the mass of 4.35 moles of aluminum?

A) 0.163 g

B) 117 g

C) 2.62 × 1024 g

D) 9.78 × 1022 g

E) 27.8 g

68) Calculate the number of moles of BaF2 in a 10.0 g sample of BaF2.

A) 9.77 mol

B) 0.115 mol

C) 17.4 mol

D) 0.0631 mol

E) 0.0570 mol

69) What is the mass of 3.5 × 1022 molecules of CO2?

A) 5.9 × 10-2 g

B) 2.6 g

C) 1.8 × 1024 g

D) 1.5 × 10-3 g

E) 3.9 g

70) Select the ionic compound that is insoluble in water.

A) Na2CO3

B) Fe(NO3)3

C) KBr

D) MgS

E) NH4Br

71) What is the precipitate that forms when solutions of Na3PO4 and Fe(NO2)3 are mixed?

A) NaNO3

B) NaFe

C) FePO4

D) PO4NO3

E) Fe3PO4

72) In an acid-base reaction, what is transferred from the acid to the base?

A) an electron

B) a hydrogen cation, H+

C) a chloride anion, Cl-

D) a sodium cation, Na+

E) a hydroxide anion, OH-

73) One atomic mass unit is the same as one gram.

74) One mole of iron contains 6.022 × 1023 grams of Fe.

75) The formula mass of a compound is calculated by adding together the number of atoms that make up the compound.

76) The term "molecular mass" is appropriately used for covalent compounds, but not ionic compounds.

77) The conversion of Fe2+ to Fe3+ is an oxidation reaction.

78) The formula mass of water is 18.02 g.

79) If the atomic mass of hydrogen is 1.01 amu, a mole of H2 will weigh 1.01 g.

80) One gram of gold (atomic mass 197 amu) contains more atoms than one gram of copper (atomic mass 63.55 amu).

81) One mole of H2O contains a total of 6.022 × 1023 atoms.

82) The law of conservation of mass states that matter cannot be gained or lost during a chemical reaction.

83) The symbol ∆, above or below the reaction arrow in an equation, indicates that heating is needed for the reaction to take place.

84) Counting the number of moles on both the reactant and product sides of an equation is the first step in balancing the equation.

85) In a properly balanced equation, the number of moles of reactants and the number of moles of products may differ.