General, organic biological chemistry, 5e chapter 7

10 In the following reaction, when the equation is correctly balanced, what is the correct coefficient for aluminum chloride?Global Outcomes: GO2 Pentane C5H12 reacts with oxygen O2 to f

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General, Organic & Biological Chemistry, 5e (Timberlake)

Chapter 7 Chemical Reactions and Quantities

7.1 Multiple-Choice Questions

1) A chemical equation is balanced when

A) the total number of molecules is the same in reactants and products

B) the total number of ions is the same in reactants and products

C) the sum of the coefficients of the reactants is equal to the sum of the coefficients of the products

D) the number of atoms of each element is the same in reactants and products

E) the charge on each atom is the same in reactants and products

Answer: D

Objective: 7.1

Global Outcomes: GO2

2) In any balanced chemical equation, the number of each type of atom on both sides of the equation is

3) Which of the following gives the balanced equation for this reaction?

K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + KNO3

A) KPO4 + CaNO3 + KNO3

B) K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + 3KNO3

C) 2K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + 6KNO3

D) 2K3PO4 + 3Ca(NO3)2 → Ca3(PO4)2 + 6KNO3

E) K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + KNO3

Answer: D

Objective: 7.1

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4) Which of the following correctly gives the best coefficients for the reaction below?N2H4 + H2O2 → N2 + H2O

5) What coefficient is placed in front of O2 to complete the balancing of the following equation?

6) What is the coefficient of hydrogen, H2, when the following equation is balanced?

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7) In this reaction, what is the coefficient for calcium oxide?

CaO(s) + CO2(g) → CaCO3(s)

8) In the following reaction, when the equation is correctly balanced, what is the correct coefficient for sodium chloride?

Pb(NO3)2(aq) + NaCl(aq) → PbCl2(s) + NaNO3(aq)

9) In the following reaction, when the equation is correctly balanced, what is the correct coefficient for H2?

Fe(s) + HCl(aq) → FeCl3(aq) + H2(g)

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10) In the following reaction, when the equation is correctly balanced, what is the correct coefficient for aluminum chloride?

Pentane (C5H12) reacts with oxygen (O2) to form carbon dioxide (CO2) and water (H2O) according to the following reaction Answer the question(s) that follow about this reaction

12) What is the coefficient for carbon dioxide in the balanced equation?

13) What is the coefficient for water in the balanced equation?

14) In a reaction, two or more elements or compounds form one product

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Objective: 7.2

15) The following reaction takes place when an electric current is passed through water It is

16) What is the classification for this reaction?

SO3 (g) + H2O (l) → H2SO4(l)

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17) The reaction of carbon with oxygen to produce carbon monoxide is an example of which class of reaction?

18) What is the classification for this unbalanced reaction?

19) The reaction of methane with oxygen to produce carbon dioxide and water is an

example of which class of reaction?

CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)

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20) Which of the following is an oxidation-reduction reaction?

A) CaCl2 + Na2SO4 → CaSO4 + 2NaCl

B) KOH + HNO3 → H2O + KNO3

C) N2 + O2 → 2NO

D) AgNO3 + NaCl → AgCl + NaNO3

E) Al2(SO4)3 + 6KOH → 2Al(OH)3 + 3K2SO4

Answer: C

Objective: 7.3

21) What is oxidized and what is reduced in the following reaction?

2Al(s) + 3Br2(g) → 2AlBr3(s)

A) Al is oxidized and Br2 is reduced

B) AlBr3 is reduced and Br2 is oxidized

C) Al is reduced and Br2 isoxidized

D) AlBr3 is reduced and Al is oxidized

E) AlBr3 is oxidized and Al is reduced

Answer: A

Objective: 7.3

22) Which of the following describes an oxidation reaction?

A) loss of electrons or loss of oxygen

B) loss of electrons or gain of oxygen

C) loss of electrons or gain of hydrogen

D) gain of electrons or gain of oxygen

E) gain of electrons or loss of H

Answer: B

Objective: 7.3

23) In an oxidation-reduction reaction, the substance oxidized alwaysA) takes on oxygen atoms

B) shows a loss of electrons

C) gives up hydrogen atoms

D) shows a gain of electrons

E) becomes a charged species

Answer: B

Objective: 7.3

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24) In this reaction, what is the substance oxidized?

25) In an oxidation-reduction reaction, the substance reduced alwaysA) takes on oxygen atoms

B) shows a loss of electrons

C) gives up hydrogen atoms

D) shows a gain of electrons

E) becomes a charged species

Answer: D

Objective: 7.3

26) How many moles of iron are present in 3.15 × 1024 atoms of iron?A) 5.23 moles

27) How many atoms of neon are present in 1.30 moles of neon?A) 3.15 × 1023atoms

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28) One mole of particles of any substance contains how many particles?A) 106

29) Avogadro's number is the number of

A) particles in 1 mole of a substance

B) amu in 1 mole of a substance

C) grams in 1 mole of a substance

D) moles in 6.02 × 1023grams of an element

E) moles in 6.02 × 1023amu of an element

Answer: A

Objective: 7.4

30) How many molecules of water, H2O, are present in 75.0 g of H2O?A) 75.0 molecules

31) How many hydrogen atoms are present in 75.0 g of H2O?

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32) The molar mass of potassium is

33) One mole of helium gas has a mass of

34) How many moles of water, H2O, are present in 75.0 g of H2O?A) 4.41 moles

35) 0.100 mole of lithium has a mass of

36) Calculate the molar mass of potassium chloride, KCl

37) What is the molar mass of copper(II) sulfate, CuSO4?

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Answer: D

Objective: 7.5

38) Calculate the molar mass of magnesium chloride, MgCl2

39) What is the molar mass of sodium phosphate, Na3PO4?

40) How many moles of carbon atoms are there in 0.500 mole of C2H6?A) 0.500 moles

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41) What is the molar mass of sucrose (C12H22O11)?

42) One mole of neon atoms has a mass of

43) The molar mass of C3H8O2 is

44) The molar mass of calcium hydroxide, Ca(OH)2, is

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45) What is the molar mass of Mg3(PO4)2, a substance formerly used in medicine as an antacid?

46) 4.00 moles of sodium have a mass of

47) How many moles of K2SO4 are in 15.0 g of K2SO4?

48) 3.00 moles of NO2 have a mass of

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49) 1.25 moles of PbO2 have a mass of

50) How many grams of Fe2O3 are there in 0.500 mole of Fe2O3?

51) How many grams of glucose (C6H12O6) are in 3.55 moles of glucose?A) 180 g

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52) Given the following equation, what is the correct form of the conversion factor needed toconvert the number of moles of O2 to the number of moles of Fe2O3produced?

4Fe(s) + 3O2 (g) → 2Fe2O3(s)

For the question(s) that follow, consider the following equation

54) The number of moles of MgO produced when 0.20 mole of O2reacts completely isA) 0.10 mole

B) 0.20 mole

C) 0.40 mole

D) 0.60 mole

E) 0.80 mole

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55) How many moles of magnesium are needed to react with 0.50 mole of O2?

56) When 4 moles of aluminum are allowed to react with an excess of chlorine gas, Cl2, how many moles of aluminum chloride are produced?

57) In the reaction of nitrogen gas, N2, with hydrogen gas, H2, to form ammonia gas, NH3 , how many moles of hydrogen are needed to react with two moles of nitrogen?

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For the question(s) that follow, consider the following balanced equation.

Mg3N2(s) + 6H2O(l) → 3Mg (OH)2(s) + 2NH3(g)

58) What is the correct form of the conversion factor needed to convert the number of moles

of H2O to the number of moles of NH3produced?

59) When 2 moles of Mg3N2 are allowed to react, how many moles of H2O also react?

For the question(s) that follow, consider the following equation

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For the question(s) that follow, consider the following balanced equation.

62) When 36.0 g of H2O react, how many grams of NH3 are produced?

63) How many grams of hydrogen are needed to produce 1.80 g of water according to this equation?

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64) In the reaction of silver nitrate with sodium chloride, how many grams of silver chloride will be produced from 100 g of silver nitrate when it is mixed with an excess of sodium chloride? The equation for the reaction is below.

AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq)

65) Find the mass of AlCl3 that is produced when 25.0 grams of Al2O3 react with excess HCl according to the following equation

Al2O3(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2O(l)

66) How many grams of NO are required to produce 145 g of N2 in the following reaction?

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67) How many grams of N2 are produced from 100 g of NH3 in the following reaction?

68) How many grams of CO2 are produced from 125 g of O2 and excess CH4?

CH4 + 2O2 → CO2 + 2H2O

69) When 3.05 moles of CH4 are mixed with 5.03 moles of O2 the limiting reactant is CH4 + 2O2 → CO2 + 2H2O

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70) When 85.0 g of CH4 are mixed with 160 g of O2 the limiting reactant is

CH4 + 2O2 → CO2 + 2H2O

71) When 10.0 g of NH3 reacts, the actual yield of N2 is 8.50 g What is the percent yield?

72) When 85.0 g of CH4 are mixed with 160 g of O2 what is the maximum amount of CO2 that can be produced?

CH4 + 2O2 → CO2 + 2H2O

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73) When 60.0 g of CH4 reacts with excess O2, the actual yield of CO2 is 112 g What is the percent yield?

CH4 + 2O2 → CO2 + 2H2O

74) Find the mass of AlCl3 that is produced when 10.0 grams of Al2O3 react with 10.0 g of HCl according to the following equation

Al2O3(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2O(aq)

75) What type of reaction is: CH4 + 2O2 → CO2 + 2H2O + 218 kcal?

76) How many kcal are produced when 32.0 g of CH4 react?

CH4 + 2O2 → CO2 + 2H2O + 218 kcal

77) For the reaction: 2H2O(l) + 137 kcal → 2H2 (g) + O2 (g), how many kcal are needed to form 2.00 moles O2 (g)?

A) 68.5 kcal

B) 137 kcal

C) 274 kcal

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D) 190 kcal

E) 548 kcal

Answer: C

Objective: 7.9

78) For the reaction: 2H2O(l) + 137 kcal → 2H2 (g) + O2 (g), how many kcal are needed to react 50.0 g H2O(l)?

79) If the reaction shown below is exothermic, the energy level of the reactants is

H2 + O2 → 2H2O

A) lower than that of the products

B) higher than that of the products

C) the same as that of the products

D) possibly lower, possibly higher than that of the products

E) higher than the activation energy of the reaction

Answer: B

Objective: 7.9

80) In an endothermic reaction

A) heat flows out of the system

B) energy is absorbed by the system

C) the temperature of the system increases

D) the products have less energy that the reactants

E) the products have the same energy that the reactants

Answer: B

Objective: 7.9

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81) Any reaction that absorbs 150 kcal of energy can be classified as

82) The is the energy difference between reactants and products in a chemical reaction

83) The is the minimum energy needed for a chemical reaction to begin

84) A reaction that releases energy as it occurs is classified as a(n)

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Barium chloride and sodium sulfate react according to the following equation.

BaCl2 + Na2SO4 → BaSO4 + 2NaCl

Answer the question(s) that follow about this reaction.

2) How many moles of barium sulfate are produced from 0.100 mole of barium chloride?A) 0.0100 mole

3) How many grams of barium sulfate can be produced from 20.8 g of barium chloride?A) 1.37 g

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4) How many grams of barium chloride are needed to make 100 grams of barium sulfate?A) 44.9 g

Answer the question(s) that follow about the following reaction.

6) How many grams of water will 100 grams of hydrogen peroxide (H2O2) produce?

7) How many grams of hydrogen peroxide (H2O2) are needed to produce 25.0 g of oxygen?A) 106 g

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8) How many moles of hydrogen peroxide (H2O2) are needed to produce 5.0 moles of water?A) 1.0 mole

7.3 Short Answer Questions

1) What type of reaction is the following?

2KClO3 → 2KCl + 3O2

Answer: decomposition reaction

Objective: 7.2

Zn + 2HCl → ZnCl2 + H2

Answer: single replacement reaction

Objective: 7.2

Answer: decomposition reaction

Objective: 7.2

Zn + 2HCl → ZnCl2 + H2

Answer: single replacement reaction

Objective: 7.2

5) The number of particles in 1 mole of hydrogen gas is

Answer: 6.02 × 1023

Objective: 7.4

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6) The molar mass of copper(II) nitrate, Cu(NO3)2 is .

Answer: 187.6 g

Objective: 7.5

7) What is the mass of 1 mole of argon gas?

Answer: 40.0 g

Objective: 7.5

8) What is the mass of 1 mole of helium gas?

Answer: 4.00 g

Objective: 7.5

9) Acetylene gas, C2H2, reacts with oxygen according to the following equation If 1.00 mole

of acetylene reacts completely with sufficient oxygen, how many moles of carbon dioxide are produced?

2C2H2 + 5O2 → 4CO2 + 2H2O

Answer: 2.00 moles of CO2

2) The following is a decomposition reaction

Answer: TRUE

Objective: 7.2

3) Loss of electrons is an oxidation

Answer: TRUE

Objective: 7.3

4) Avogadro's number is the number of grams in a mole

Answer: FALSE

Objective: 7.4

5) The molar mass of silver is 47 g

Answer: FALSE

Objective: 7.5

6) The molar mass of magnesium is 24.3 g

Answer: TRUE

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Objective: 7.5

7) The mass of one mole of water is 18.0 g

Answer: TRUE

Objective: 7.5

8) The molar mass of chlorine gas is 35.5 g

Answer: FALSE

Objective: 7.5

9) The molar mass of copper(II) chloride is 134.5 g

Answer: TRUE

Objective: 7.5

10) In the reaction of hydrogen gas with oxygen gas to produce water, 1 mole of oxygen gas can produce 2 moles of water, given sufficient hydrogen available

Answer: TRUE

Objective: 7.6

11) In the reaction of hydrogen gas with oxygen gas to produce water, 16.0 g of oxygen gas can produce

9.00 g of water, given sufficient hydrogen available

2H2 + O2 → 2H2O

Answer: FALSE

Objective: 7.7

12) The % yield is the ratio of the theoretical yield to the actual yield multiplied by 100.Answer: FALSE

Objective: 7.9

13) In an exothermic reaction, heat is a product

Answer: TRUE

Objective: 7.9

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