Download General Chemistry, 9e (Petrucci)

General Chemistry, 9e (Petrucci)
Chapter 4 Chemical Reactions
1) A formula is a shorthand way of representing a chemical reaction.
Answer:
True
False
Diff: 1
Reference: Section 4-1
2) In a balanced equation, the number of atoms of each element in the products must equal to
the number of atoms of each element in the reactants.
Answer:
True
False
Diff: 1
Reference: Section 4-1
3) (aq) indicates that the compound is dissolved in alcohol.
Answer:
True
False
Diff: 1
Reference: Section 4-1
4) In a chemical equation, Δ above the yield sign means the reaction will produce heat.
Answer:
True
False
Diff: 1
Reference: Section 4-1
5) In a solution of alcohol and water that is 70 % water, alcohol is the solvent.
Answer:
True
False
Diff: 1
Reference: Section 4-3
6) A chemical equation is a shorthand way of representing a chemical reaction.
Answer:
True
False
Diff: 1
Reference: Section 4-3
7) Calculations of the amounts of reactants used or products formed are called stoichiometry.
Answer:
True
False
Diff: 1
Reference: Section 4-3
8) The numbers in front of formulas in balanced equations are called stoichiometric
coefficients.
Answer:
True
False
Diff: 1
Reference: Section 4-3
9) Molarity is defined as moles of solute per kg of solution.
Answer:
True
False
Diff: 1
Reference: Section 4-3
10) The solvent determines the state of the solution.
Answer:
True
False
Diff: 1
Reference: Section 4-3
11) How many grams of N2 are required to react with 2.30 moles of Mg in the following
process?
3 Mg + N2 → Mg3N2? (Mg = 24.3, N = 14.0 g/mol)
A) (2.30/3)(28.0)
B) (2.30/3)
C) (2.30)(28.0)
D) (2.30/3)/28.0
E) (2.30)(3)(28.0)
Answer: A
Diff: 1
Reference: Section 4-2
12) How many moles of H3PO4 are produced when 20.0 g of HCl are produced by the reaction
PC15 + 4 H2O → H3PO4 + 5 HCI?
(P = 31.0, Cl = 35.5, H = 1.0, O = 16.0 g/mol)
A) (20.0/36.5)
B) (20.0/35.5)/5
C) (20.0/36.5)/5
D) (20.0/98.0)
E) (20.0/98.0)/5
Answer: C
Diff: 1
Reference: Section 4-2
13) For the reaction 2 A1+ Fe2O3 → Al2O3 + 2 Fe, 2.5 g of A1 (27.0 g/mol) and 7.2 g of Fe2O3
(159.8 g/mol) produce how many g of Fe (55.9 g/mol)?
A) 2.5 (55.9/27.0)
B) 2.5 (55.9)(2)/(27.0)(2)
C) 7.2 (55.9)(2)/158.9
D) 7.2 (55.9/158.9)
E) 2.5 (55.9/158.9)
Answer: C
Diff: 1
Reference: Section 4-2
14) Which metal will produce the most hydrogen per gram of metal?
A) 2 Li + 2 HCl → 2 LiCl + H2
B) Sn + 4 HCl → SnCl4 + 2 H2
C) 2 Fe + 6 HCl →2 FeCl3 + 3 H2
D) Mg + 2 HCl → MgCl2 + H2
E) 2 Cr + 6 HCl → 2 CrCl3 + 3H2
Answer: A
Diff: 2
Reference: Section 4-2
15) Potassium superoxide (KO2) can simulate a plant-type action by consuming carbon dioxide
gas and releasing oxygen gas. The other product is potassium carbonate. When the equation
for this process is balanced, it shows that:
A) 3 mol oxygen is produced per mol KO2 consumed
B) 2 mol KO2 is consumed per mol carbon dioxide
C) moles of reactants equals moles of product
D) 3 g of oxygen is produced per 2 g CO2 consumed
E) moles of products exceed moles of reactants
Answer: B
Diff: 3
Reference: Section 4-2
16) Gases emitted during volcanic activity often contain high concentrations of hydrogen sulfide
and sulfur dioxide. These gases may react to produce deposits of sulfur according to the
equation: 2 H2S(g) + SO2(g) → 3 S(s) + 2 H2O (g)
For the complete reaction of 6.41 mol of hydrogen sulfide:
A) 308 g of sulfur is formed
B) 410 g of sulfur dioxide is consumed
C) 231 g of water vapor is produced
D) 320 g of total products result
E) 628 g of total reactants are consumed
Answer: A
Diff: 3
Reference: Section 4-2
17) Which of the following processes could theoretically produce the maximum mass of oxygen
per gram of metal salt reactant?
A) 2 KClO3 → 2 KCl + 3 O2
B) 4 KO2 + 2 CO2 → 2 K2CO3 + 3 O2
C) 2 Na2O2 + 2 H2SO4 → 2 H2O + O2
D) 2 HgO → 2 Hg + O2
E) NaBrO2 → NaBr + O2
Answer: A
Diff: 3
Reference: Section 4-2
18) Choose the INCORRECT statement.
A) A chemical equation is a shorthand way of representing a chemical reaction.
B) Calculations of the amounts of reactants used or products formed are called
stoichiometry.
C) The numbers in front of formulas in balanced equations are called stoichiometric
coefficients.
D) Molarity is defined as moles of solute per kg of solution.
E) The solvent determines the state of the solution.
Answer: D
Diff: 1
Reference: Section 4-3
19) Which of the following represents a 1.00 M aqueous solution of glucose (C 6H12O6)?
A) 90.0 g glucose per 500 mL water
B) 10.0 g glucose per 10.0 mL water
C) 0.180 g glucose per mL solution
D) 0.100 g glucose per mL solution
E) 4.5 g glucose per 4.5 g water
Answer: C
Diff: 1
Reference: Section 4-3
20) For the reaction symbolized as HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l) water is both:
A) a reactant and the solute
B) a reactant and the solvent
C) a product and the solute
D) a product and the solvent
E) a liquid and the intermediate
Answer: D
Diff: 1
Reference: Section 4-3
21) How many mL of 0.024 M solution can be produced from 14.1 mL of 3.0 M solution?
A) (14.1)(0.024)(3.0)
B) 14.1(0.024/3.0)
C) 14.1(3.0/0.024)
D) (14.1/0.024)/3.0
E) none of these
Answer: C
Diff: 1
Reference: Section 4-3
22) 52.5 mL of a solution were diluted to a volume of 6.25 L and then had a concentration of 3.16
M. What was the molarity of the concentrated solution?
A) 3.16(52.5/6.25)
B) 3.16(6.25/52.5)
C) (3.16)(52.5)(6.25)
D) 3.16(52.5/6250)
E) (6.25)(3.16)/0.0525
Answer: E
Diff: 1
Reference: Section 4-3
23) If 85.6 mL of a 6.75 M solution are diluted to 6.20 L with water, what is the concentration of
the final solution?
A) 6.75 (6.20/85.6)
B) 6.75 (8.56/6.20)
C) 6.75 (6200/85.6)
D) 6.75 (85.6/6200)
E) 8.56 (6.20/6.75)
Answer: D
Diff: 1
Reference: Section 4-3
24) If 5.97 mL of a solution contains 2.54 mg of sodium ion, what is the molarity of the sodium
chloride solution?
A) 0.425 M
B) 1.85 × 10-2 M
C) 1.85 × 10-5 M
D) 7.28 × 10-3 M
E) 0.102 M
Answer: B
Diff: 2
Reference: Section 4-3
25) When the equation K2S2O3 + I2 → K2S4O6 + KI is balanced with the smallest integer
coefficients, the coefficient of KI is:
A) 2
B) 1
C) 3
D) 4
E) 5
Answer: A
Diff: 1
Reference: Section 4-1
26) When the equation Fe2(C2O4)3 → FeC2O4 + CO2 is balanced with the smallest integer
coefficients, the coefficient of CO2 is:
A) 1
B) 2
C) 4
D) 3
E) 5
Answer: B
Diff: 1
Reference: Section 4-1
27) When the equation CS2 + Cl2 → CCl4 + S2Cl2 is balanced with the smallest integer
coefficients, the sum of the coefficients is:
A) 5
B) 6
C) 4
D) 3
E) 7
Answer: B
Diff: 1
Reference: Section 4-1
28) What is the sum of the coefficients when the following is balanced?
K2O + H2O → KOH
A) 2
B) 6
C) 3
D) 8
E) 4
Answer: E
Diff: 1
Reference: Section 4-1
29) What is the sum of the coefficients when the following is balanced?
Na + HCl → NaCl + H2
A) 7
B) 4
C) 2
D) 10
E) 9
Answer: A
Diff: 1
Reference: Section 4-1
30) What is the sum of the coefficients when the following is balanced?
Al + Fe2O3 → Al2O3 + Fe
A) 4
B) 6
C) 12
D) 9
E) 8
Answer: B
Diff: 1
Reference: Section 4-1
31) What is the sum of the coefficients when the following is balanced?
CaC2(s) + H2O(l) → Ca(OH)2(s) + C2H2(g)
A) 8
B) 4
C) 5
D) 10
E) 9
Answer: C
Diff: 1
Reference: Section 4-1
32) What is the sum of the coefficients when the following is balanced?
KClO3(s) → KCl(s) + O2(g)
A) 11
B) 10
C) 5
D) 7
E) 6
Answer: D
Diff: 1
Reference: Section 4-1
33) What is the sum of the coefficients when the following is balanced?
PCl3(l) + Cl2(g) + P4O10(s) → POCl3(l)
A) 3
B) 18
C) 45
D) 10
E) 23
Answer: E
Diff: 1
Reference: Section 4-1
34) What is the sum of the coefficients when the following is balanced?
Al(s) + HCl(aq) → AlCl3(aq) + H2(g)
A) 13
B) 11
C) 18
D) 19
E) 21
Answer: A
Diff: 1
Reference: Section 4-1
35) What is the sum of the coefficients when the following is balanced?
H2(g) + O2(g) → H2O(l)
A) 4
B) 5
C) 8
D) 9
E) 7
Answer: B
Diff: 1
Reference: Section 4-1
36) What is the sum of the coefficients when the following is balanced?
C2H6 + O2 → CO2 + H2O
A) 5
B) 10
C) 19
D) 21
E) 25
Answer: C
Diff: 1
Reference: Section 4-1
37) What is the sum of the coefficients when the following is balanced?
CH3OH → CO + H2
A) 3
B) 8
C) 5
D) 4
E) 7
Answer: D
Diff: 1
Reference: Section 4-1
38) What is the sum of the coefficients when the following equation is balanced?
H2SO3 + Al(OH)3 → Al2(SO3)3 + H2O
A) 4
B) 5
C) 11
D) 12
E) 14
Answer: D
Diff: 2
Reference: Section 4-1
39) Write the complete balanced equation for the complete combustion reaction expected to
occur between C3H7OH and O2.
A) C3H7OH + O2 → 3 CO2 + 4 H2O
B) 2 C3H7OH + 9 CO2 → 6 CO2 + 8 H2O + 9 C
C) 2 C3H7OH + 6 CO2 → CO + 8 H2O
D) 2 C3H7OH + 9 O2 → 6 CO2 + 8 H2O
E) 2 C3H7OH + 9 O2 → 6 C + 8 H2 + 10 O2
Answer: D
Diff: 3
Reference: Section 4-1
40) What is the sum of the coefficients in the balanced equation that represents the complete
combustion of the relatively new gasoline additive "MTBE," for which the molecular formula
is C5H12O?
A) 39
B) 37
C) 29
D) 24
E) 20
Answer: A
Diff: 3
Reference: Section 4-1
41) Iron metal reacts with chlorine gas as follows:
2 Fe(s) + 3 Cl2(g) → 2 FeCl3(s)
How many moles of FeCl3 are obtained when 4.6 mol of Cl 2 reacts with excess Fe?
A) 3.1 mol
B) 4.6 mol
C) 1.5 mol
D) 2.3 mol
E) 6.9 mol
Answer: A
Diff: 1
Reference: Section 4-2
42) 24.0 g of ethane (C2H6) are burned to form CO2 and H2O. How many grams of CO2 are
produced?
A) 32.8 g
B) 14.4 g
C) 43.2 g
D) 35.1 g
E) 70.3 g
Answer: E
Diff: 2
Reference: Section 4-2
43) Given the following reaction:
Na2SO4(s) + 2 C(s) → Na2S(s) + 2 CO2(g)
How many grams of carbon are required to produce 18.4 g Na2S(s)?
A) 11.3 g
B) 5.66 g
C) 2.83 g
D) 239 g
E) 142 g
Answer: B
Diff: 2
Reference: Section 4-2
44) The chemical reaction occurring during the discharge of a lead storage battery can be
represented by the equation: Pb(s) + PbO2(s) + 2 H2SO4(aq) → 2 PbSO4(s) + 2 H2O(1)
What mass of lead sulfate would result from the complete reaction of 41.4 g of lead?
A) 57.6 g
B) 60.5 g
C) 105 g
D) 115 g
E) 121 g
Answer: E
Diff: 2
Reference: Section 4-2
45) A 1.900 g sample of C6H12 is burned in an excess of oxygen. What mass of CO2 and H2O
should be obtained?
A) 0.994 g CO2, 0.407 g H2O
B) 2.98 g CO2, 1.22 g H2O
C) 5.96 g CO2, 2.44 g H2O
D) 10.45 g CO2, 4.27 g G H2O
E) 5.23 g CO2, 2.38 g H2O
Answer: C
Diff: 2
Reference: Section 4-2
46) How much Cl2, in g, is required to produce 12.0 g CCl4 according to the following reaction?
CH4 + C12 → CC14 + 4 HC1
A) 12.0 g
B) 5.52 g
C) 22.1 g
D) 1.38 g
E) 11.0 g
Answer: C
Diff: 2
Reference: Section 4-2
47) Given the reaction:
2KMnO4 + 10 KI + 8 H2SO4 → 6 K2SO4 + 2 MnSO4 + 5 I2 + 8 H2O
How many moles of H2SO4 are required to produce 2.0 moles of I2, given the other
reactants are in excess?
A) 0.80 mol
B) 1.3 mol
C) 3.2 mol
D) 4.0 mol
E) 1.6 mol
Answer: C
Diff: 2
Reference: Section 4-2
48) What mass of water is produced in the metathesis reaction 75.2 g Zn(OH)2 with 43.4 g HCl?
A) 13.6 g
B) 27.2 g
C) 10.7 g
D) 21.4 g
E) 31.8 g
Answer: D
Diff: 2
Reference: Section 4-2
49) What mass of oxygen gas would be consumed by the complete combustion of 7.5 g of a
mixture of propane (C3H8) and butane (C4H10) in the mole ratio of C3H8/C4H10 = 1.33?
A) 3.9 g
B) 11 g
C) 14 g
D) 21 g
E) 27 g
Answer: E
Diff: 3
Reference: Section 4-2
50) What volume of 6.0 M sulfuric acid is required for the preparation of 500.0 mL of 0.30 M
solution?
A) 100 mL
B) 50 mL
C) 40 mL
D) 30 mL
E) 25 mL
Answer: E
Diff: 1
Reference: Section 4-3
51) What is the molarity of 10.9 g KCl dissolved in 150.0 mL of water?
A) 0.0727 M
B) 0.146 M
C) 0.975 M
D) 0.0219 M
E) 0.667 M
Answer: C
Diff: 1
Reference: Section 4-3
52) 45.8 mL of a 3.14 sodium chloride solution were used to titrate 50.0 mL of an aqueous silver
nitrate solution. What is the molarity of the silver nitrate solution?
A) 2.88 M
B) 1.50 M
C) 3.14 M
D) 3.42 M
E) 1.71 M
Answer: A
Diff: 1
Reference: Section 4-3
53) What mass of trisodium phosphate is required to prepare 250.0 mL of a solution which is
0.30 M in sodium ion?
A) 37 g
B) 12 g
C) 7.7 g
D) 4.1 g
E) 3.0 g
Answer: D
Diff: 2
Reference: Section 4-3
54) What volume of 2.0 M HCl, in mL, is required to dissolve a 10.0 g piece of Zn?
Zn(s) + 2 HCl → ZnCl2 + H2(g)
A) 76 mL
B) 330 mL
C) 170 mL
D) 310 mL
E) 150 mL
Answer: E
Diff: 2
Reference: Section 4-3
55) Our task is to measure the volume of blood in an elephant. One way to do this would be to
drain its blood into a suitable container. Aside from harmful side effects which this method
has on the elephant, it will not be successful, as blood will still remain behind in the tissues.
Hence, we will inject 2.00 ml of a 2.00 M solution of a dye which the elephant will not
appreciably metabolize or excrete in one hour and then measure the concentration of this
dye in the bloodstream (our sample being taken from another leg than the point of injection)
after 30 minutes, a sufficient time to thoroughly mix the dye in the bloodstream. The
concentration of dye at this point is 1.25 x 10-5 M What is the volume of blood in the
elephant?
A) 320. L
B) 32000 L
C) 3.2 L
D) 80 L
E) 800 L
Answer: A
Diff: 2
Reference: Section 4-3
56) What is the molarity of formaldehyde in a solution containing 0.25 g of formaldehyde
(CH2O) per mL?
A) 2.5 M
B) 25 M
C) 8.3 M
D) 83 M
E) 4.0 M
Answer: C
Diff: 2
Reference: Section 4-3
57) "Washing soda" (sodium carbonate) may be used to "soften" water by removal of certain
ions that would otherwise react with common soaps. When the "hardness" is due to calcium
ion, the "softening" process may be represented as:
Ca2+(aq) + CO32-(aq) → CaCO3(s)
What mass of sodium carbonate would be required for removal of essentially all of the
calcium ion from 750 L of solution containing 43 mg Ca 2+ per liter?
A) 85 g
B) 67 g
C) 12 g
D) 48 g
E) 22 g
Answer: A
Diff: 2
Reference: Section 4-3
58) If an aqueous solution containing 46 g of sodium carbonate per liter is mixed with an equal
volume of 0.20 M aqueous hydrochloric acid, what would be the molarity of sodium
chloride in the final solution, assuming volumes were additive?
A) 0.10 M
B) 0.20 M
C) 0.22 M
D) 0.43 M
E) 0.50 M
Answer: A
Diff: 2
Reference: Section 4-3
59) The molarity of a solution that contains 14.7 g of H 2SO4 in 200. mL solution is:
A) 1.5 M
B) 0.75 M
C) 0.77 M
D) 7.4 M
E) 3.0 M
Answer: B
Diff: 2
Reference: Section 4-3
60) What is the molarity of methanol, CH3OH (d = 0.792g/mL) if 150.0 mL is dissolved in
enough water to make 4.00 L of solution?
A) 3.71 M
B) 1.17 M
C) 1.48 M
D) 0.927 M
E) 0.734 M
Answer: D
Diff: 2
Reference: Section 4-3
61) What is the molarity of a sucrose solution (C12H22O11) if 110.0 g of a 92.0% pure solid is
dissolved per 250.0 mL of water?
A) 0.296 M
B) 1.29 M
C) 0.321 M
D) 1.40 M
E) 1.18 M
Answer: E
Diff: 2
Reference: Section 4-3
62) What volume of concentrated acetic acid (CH3CO2H, density 1.05 g mL-1) is needed to
prepare 250 mL of a 0.30 M aqueous solution?
A) 4.7 mL
B) 4.3 mL
C) 3.0 mL
D) 2.5 mL
E) 2.2 mL
Answer: B
Diff: 2
Reference: Section 4-3
63) What mass of MgCl2 in grams must be added to 250.0 mL of a 0.25 M MgCl 2 solution to
produce a 0.40 M solution assuming no change of volume upon addition?
A) 9.5 g
B) 6.0 g
C) 2.2 g
D) 3.6 g
E) 19 g
Answer: D
Diff: 3
Reference: Section 4-3
64) You have 10.00 L of a 0.350 M KCl solution, but you need a solution that is 0.450 M. What
volume of water, in L, would you evaporate from the solution?
A) 4.38 L
B) 3.50 L
C) 2.85 L
D) 7.77 L
E) 2.22 L
Answer: E
Diff: 3
Reference: Section 4-3
65) How many grams of a solid mixture containing strontium chloride would one need to make
558 ml of a 0.100 M strontium chloride solution, if the solid mixture contains 58.6%
strontium chloride by weight?
A) 6.62 g
B) 15.1 g
C) 8.85 g
D) 5.19 g
E) 9.52 g
Answer: B
Diff: 3
Reference: Section 4-3
66) To measure the volume of an irregularly shaped container filled with water, 1.00 mL of 2.00
M potassium chloride solution is added. After stirring, a 5.00 mL sample was found to
contain 2.54 × 10-2 mg of potassium ion. What is the volume of the container?
A) 15.4 L
B) 29.4 L
C) 2.94 × 104 L
D) 3.97 × 10-4 L
E) 2.54 L
Answer: A
Diff: 3
Reference: Section 4-3
67) Given the reaction:
2 KMnO4 + 10 KI + 8 H2SO4 → 6 K2SO4 + 2 MnSO4 + 5I2 + 8H2O
How many moles of K2SO4 are produced by allowing five moles each of KMnO4, KI and
H2SO4 to react?
A) 3 mol
B) 1 mol
C) 2 mol
D) 4 mol
E) 5 mol
Answer: A
Diff: 1
Reference: Section 4-4
68) How many grams of CrSO4 will be made from 25.0 grams each of Zn, K2Cr2O7, and
H2SO4?
4 Zn + K2Cr2O7 + 7 H2SO4 → 4 ZnSO4 + 2 CrSO4 + K2SO4 + 7 H2O
A) 10.8
B) 28.3
C) 25.2
D) 12.6
E) 37.8
Answer: A
Diff: 1
Reference: Section 4-4
69) How many grams of ZnSO4 will be made from 41.0 grams each of Zn, K2Cr2O7, and
H2SO4?
4 Zn + K2Cr2O7 + 7 H2SO4 → 4 ZnSO4 + 2 CrSO4 + K2SO4 + 7 H2O
A) 67.6
B) 38.6
C) 101
D) 20.6
E) 82.5
Answer: B
Diff: 1
Reference: Section 4-4
70) Given the reaction:
2 KMnO4 + 10 KI + 8 H2SO4 → 6 K2SO4 + 2 MnSO4 + 5 I2 + 8 H2O
How many moles of I2 are produced by reacting 28.0 g KMnO4, 18.0 g KI and 46.0 g H2SO4?
A) 0.108 mol
B) 0.0542 mol
C) 0.293 mol
D) 0.443 mol
E) 0.886 mol
Answer: B
Diff: 2
Reference: Section 4-4
71) The chemical reaction during low current discharge of a simple "dry cell" involves:
(unbalanced) Zn + MnO2 + NH4Cl → ZnCl2 + Mn2O3 + NH3 + H2O
What is the coefficient for zinc in the balanced equation, and what is the limiting reagent for
a process in which equal masses of reactants are mixed?
A) 1/Zn
B) 2/Zn
C) 1/MnO2
D) 2/MnO2
E) 2NH4Cl
Answer: C
Diff: 3
Reference: Section 4-4
72) The chemical reaction occurring during the discharge of a lead storage battery can be
represented by the equation:
Pb(s) + PbO2(s) +2 H2SO4(aq) → 2 PbSO4(s) + 2 H2O(l)
Which is the limiting reagent and the amount of PbSO4 produced if 53.0 g of Pb, 77.3 g of
PbO2 and 534 mL of 0.544 M solution of H2SO4 is used?
A) PbO2, 196 g
B) Pb, 77.6 g
C) Pb, 155 g
D) H2SO4, 88.1 g
E) H2SO4, 176 g
Answer: D
Diff: 1
Reference: Section 4-5
73) The chemical reaction occurring during the discharge of a lead storage battery can be
represented by the equation:
Pb(s) + PbO2(s) + 2 H2SO4(aq) → 2 PbSO4(s) + 2 H2O(l)
Which is the limiting reagent and the amount of PbSO 4 produced if 39.8 g of Pb, 57.9 g of
PbO2 and 352 mL of 0.375 M solution of H2SO4 is used?
A) PbO2, 146 g
B) Pb, 58.2 g
C) Pb, 116 g
D) H2SO4, 80.0 g
E) H2SO4, 40.0 g
Answer: E
Diff: 1
Reference: Section 4-5
74) What is the percent yield if 185 grams of SiO2 are made from 328 g of Cr2O3 by the
following equation?
3 Si(s) + 2 Cr2O3(s) → 3 SiO2(s) + 4 Cr(l)
A) 142%
B) 70%
C) 56%
D) 105%
E) 95%
Answer: E
Diff: 1
Reference: Section 4-5
75) What is the percent yield if 122 grams of SiO2 are made from 246 g of Cr2O3 by the
following equation?
3 Si(s) + 2 Cr2O3(s) → 3 SiO2(s) + 4 Cr(l)
A) 83.6%
B) 49.6%
C) 125%
D) 33.1%
E) 59.3%
Answer: A
Diff: 1
Reference: Section 4-5
76) If 0.500 mol of CaCl2 is mixed with 0.200 mol Na3PO4, the maximum amount in moles of
Ca3(PO4)2 that can be formed is:
A) 0.17
B) 0.20
C) 0.10
D) 0.67
E) 0.50
Answer: C
Diff: 1
Reference: Section 4-5
77) Consider the equation:
2 Na + 2 H2O → 2 NaOH + H2.
If 92.0 g of sodium is reacted with 76.0 g of water until the reaction goes to completion,
which reactant will remain and in what quantity?
A) 72.0 g water
B) 43.5 g sodium
C) 3.9 g water
D) 10.0 g sodium
E) 10.0 g water
Answer: C
Diff: 2
Reference: Section 4-5
78) 42.6 g Cu are combined with 84.0 g of HNO3 according to the reaction:
3 Cu + 8 HNO3 → 3 Cu(NO3)2 + 2 NO + 4 H2O.
Which reagent is limiting and how many grams of Cu(NO3)2 are produced?
A) Cu, 93.8 g
B) HNO3, 93.8 g
C) Cu, 125.6 g
D) HNO3, 125.6 g
E) Cu(NO3)2, 125.6 g
Answer: B
Diff: 2
Reference: Section 4-5
79) Consider the gaseous reaction:
N2H4(g) + 3 O2(g) → 2 NO2(g) + 2 H2O(g)
If the above reaction has a percent yield of 98.5%, what mass in grams of oxygen is needed
to produce 49.0 g of NO2(g)?
A) 50.4 g
B) 51.9 g
C) 25.9 g
D) 23.1 g
E) 11.5 g
Answer: B
Diff: 2
Reference: Section 4-5
80) How many grams of sulfuric acid, H2SO4, can be obtained from 578 grams of iron ore if the
ore is 76.0% FeS? The reactions involved are given below. Each reaction is 92.0% efficient.
4 FeS + 7O2 → 2 Fe2O3 + 4 SO2
2 SO2 + O2 → 2 SO3
SO3 + H2O → H2SO4
A) 502 g
B) 307 g
C) 382 g
D) 95.5 g
E) 629 g
Answer: C
Diff: 2
Reference: Section 4-5
81) The Haber Process for production of ammonia is represented by:
3 H2(g) + N2(g) → 2 NH3(g)
If a mixture of 30 g of hydrogen with 10 g of nitrogen produced 8.4 g of ammonia, what was
the percent yield?
A) 84%
B) 69%
C) 49%
D) 28%
E) 20%
Answer: B
Diff: 2
Reference: Section 4-5
82) Sulfuric acid can be prepared by a multistep process summarized as:
2 SO2 + O2 + 2 H2O → 2 H2SO4
What mass of sulfuric acid could be produced daily by a process using 38 kg per day of
sulfur dioxide with a 70% conversion efficiency ("yield"), assuming that sulfur dioxide is the
limiting reagent?
A) 27 kg/day
B) 41 kg/day
C) 54 kg/day
D) 58 kg/day
E) 83 kg/day
Answer: B
Diff: 2
Reference: Section 4-5
83) Nitroglycerin, used both in medicine and as an explosive, can be prepared by the carefully
controlled reaction of glycerol (C3H8O3) with nitric acid, as symbolized by:
C3H8O3 + 3 HNO3 → C3H5N3O9 + 3 H2O
What mass of nitric acid is required for the production of 2.8 g of nitroglycerin by a process
having a 67% yield?
A) 2.3 g
B) 0.39 g
C) 1.6 g
D) 3.5 g
E) 1.2 g
Answer: D
Diff: 2
Reference: Section 4-5
84) Chromium in its +VI oxidation state is considered a hazardous, carcinogenic species,
destruction of which may be accomplished by the process symbolized as:
4 Zn + K2Cr2O7 + 7 H2SO4 → 4 ZnSO4 + 2 CrSO4 + K2SO4 + 7 H2O
If 1.0 mol of each reactant is mixed, what is the limiting reagent, and what is the theoretical
yield of chromium(II) sulfate?
A) Zn,0.50 mol
B) K2Cr2O7,2.0 mol
C) H2SO4,0.29 mol
D) H2,1.0 mol
E) no limiting reagent, 1.0 mol
Answer: C
Diff: 2
Reference: Section 4-5
85) Given the reaction:
P4(l) + 6 Cl2(g) → 4 PCl3(l)
If the percent yield is 82%, what mass of P4 is required to obtain 2.30 g PCl3 (Cl2 in excess)?
A) 0.63 g
B) 0.52 g
C) 0.43 g
D) 0.16 g
E) 0.95 g
Answer: A
Diff: 2
Reference: Section 4-5
86) In the following reaction:
2 KClO3(s) → 2 KCl(s) + 3 O2(g)
14.0 g KClO3 yielded 1.40 g KCl. What is the percent yield?
A) 6.08%
B) 16.4%
C) 11.0%
D) 32.9%
E) 10.0%
Answer: B
Diff: 2
Reference: Section 4-5
87) Cryolite is a compound needed for the Hall-Heroult process for producing aluminum.
Cryolite is produced by the following reaction:
6 HF + Al(OH)3 + 3 NaOH → Na3AlF6 + 6 H2O
How many grams of cryolite are produced if the reaction has a 67.3% yield and a limiting
reagent of 35.4 grams of NaOH?
A) 61.9
B) 41.7
C) 125
D) 186
E) 20.2
Answer: B
Diff: 2
Reference: Section 4-5
88) Cryolite is a compound needed for the Hall-Heroult process for producing aluminum.
Cryolite is produced by the following reaction:
6 HF + Al(OH)3 + 3 NaOH → Na3AlF6 + 6 H2O
How many grams of cryolite are produced if the reaction has a 94.3% yield and a limiting
reagent of 27.8 grams of HF?
A) 275
B) 48.6
C) 45.8
D) 15.0
E) 15.9
Answer: C
Diff: 2
Reference: Section 4-5
89) One source of iodine is sodium iodate. Iodine is produced by a series of reactions. The first
reaction is a reduction reaction with sodium hydrogen sulfite.
IO3- (aq) + 3 HSO3- (aq) → I- (aq) + 3 SO42- (aq) + 3 H+ (aq)
5 I- (aq) + IO3- (aq) + 6 H+ (aq) → 3 I2(s) + 3 H2O
How many grams of iodine are produced from 1.00 × 102 grams of NaHSO3?
A) 81.3
B) 243
C) 62.6
D) 48.8
E) 205
Answer: D
Diff: 2
Reference: Section 4-5
90) One source of iodine is sodium iodate. Iodine is produced by a series of reactions. The first
reaction is a reduction reaction with sodium hydrogen sulfite.
IO3-( aq) + 3 HSO3- (aq) → I- (aq) + 3 SO42- (aq) + 3 H+(aq)
5 I- (aq) + IO3- (aq) + 6 H+ (aq) → 3 I2(s) + 3 H2O
How many grams of iodine are produced from 1.00 × 102 grams of NaHSO3 if each reaction
has a 95.0% yield?
A) 48.8
B) 51.4
C) 185
D) 46.3
E) 44.0
Answer: E
Diff: 2
Reference: Section 4-5
91) If 8.52 g each of zinc, potassium dichromate, and sulfuric acid are reacted by the reaction:
4 Zn + K2Cr2O7 + 7 H2SO4→ 4 ZnSO4 + 2 CrSO4 +K2SO4 + 7 H2O
How many grams of zinc will be left unreacted?
A) 0.94 g
B) 3.65
C) 5.27
D) 1.89
E) 3.25
Answer: C
Diff: 3
Reference: Section 4-5
92) If 8.52 g each of zinc, potassium dichromate, and sulfuric acid are reacted by the reaction:
4 Zn + K2Cr2O7 + 7 H2SO4→ 4 ZnSO4 + 2 CrSO4 +K2SO4 + 7 H2O
How many grams of potassium dichromate will be left unreacted?
A) 1.05
B) 2.84
C) 7.30
D) 4.87
E) 3.65
Answer: D
Diff: 3
Reference: Section 4-5
93) In the reaction: 4 Zn + K2Cr2O7 + 7 H2SO4→ 4 ZnSO4 + 2 CrSO4 +K2SO4 + 7 H2O, if 25.4 g
of zinc sulfate si to be made, how many grams of potassium dichromate is required?
A) 13.9
B) 3.48
C) 46.3
D) 6.35
E) 11.6
Answer: E
Diff: 3
Reference: Section 4-5
94) If the percent yield is 82.0%, how many grams of silicon is needed to make 105 g of
chromium by the reaction: 3 Si (s) + 2 Cr203 (s) → 3 SiO2 (s) + 4 Cr (l)?
A) 51.9 g
B) 92.2 g
C) 42.5 g
D) 34.9 g
E) 13.0 g
Answer: A
Diff: 3
Reference: Section 4-5
95) Acetylene gas may be produced by carefully adding water to calcium carbide, according to
the equation:
CaC2(s) + 2 H2O(l) → Ca(OH)2(s) + C2H2(g)
When a 37 g sample of an impure calcium carbide was treated with excess water, 13 g of
acetylene gas was produced. If the reaction is essentially 100% efficient, what was the
percentage of nonreacting impurity in the carbide sample?
A) 86%
B) 58%
C) 42%
D) 35%
E) 14%
Answer: E
Diff: 3
Reference: Section 4-5
96) Given the following reactions:
Fe + Br2 → FeBr2
3 FeBr2 + Br2 → Fe3Br8
If each reaction is 82.0% efficient, what mass of Fe3Br8 is produced from 1.00 g Fe?
A) 4.81 g
B) 3.94 g
C) 2.65 g
D) 3.24 g
E) 2.57 g
Answer: D
Diff: 3
Reference: Section 4-5
97) 306 mL of a 0.208 M solution of silver nitrate will react with 146 mL of a 0.170 M solution of
sodium phosphate to produce how many grams of silver phosphate precipitate? The
balanced reaction is:
3 AgNO3 + Na3PO4 → Ag3PO4 + 3 NaNO3
A) 8.88 g
B) 26.6 g
C) 14.2 g
D) 10.4 g
E) 1.51 g
Answer: A
Diff: 3
Reference: Section 4-5
98) How many grams of sulfuric acid, H2SO4, can be obtained from 400 grams of iron ore if the
ore is 80.0% FeS? The reactions involved are given below. Each reaction is 100% efficient.
4 FeS + 7O2 → 2 Fe2O3 + 4 SO2
2 SO2 + O2 → 2 SO3
SO3 + H2O → H2SO4
A) 557 g
B) 446 g
C) 357 g
D) 287 g
E) 89.3 g
Answer: C
Diff: 3
Reference: Section 4-5
99) How many grams of iron (II) sulfide is required to make 225 g of sulfuric acid, H 2SO4? The
reactions involved are given below. Each reaction is 100% efficient.
4 FeS + 17O2 → 2 Fe2O3 + 4 SO2
2 SO2 + O2 → 2 SO3
SO3 + H2O → H2SO4
A) 101 g
B) 251 g
C) 126 g
D) 202 g
E) 502 g
Answer: D
Diff: 3
Reference: Section 4-5
100) Given the following reactions:
Fe + Br2 → FeBr2
3 FeBr2 + Br2 → Fe3Br8
If each reaction is 82.0% efficient, what mass of iron is necessary to make 8.45 g of Fe3Br8?
A) 0.870 g
B) 3.73 g
C) 2.14 g
D) 1.75 g
E) 2.61 g
Answer: E
Diff: 3
Reference: Section 4-5
101) What thickness (in cm) is the silicon block (density = 2.33 g/cm3) that is 2.87 cm wide and
long necessary to react with 91.3 g of Cr2O3 by the reaction: 3 Si (s) + 2 Cr2O3 (s) → 3 SiO2
(s) + 4 Cr (l)?
A) 2.05
B) 1.32
C) 3.08
D) 8.98
E) 3.79
Answer: B
Diff: 3
Reference: Section 4-5