Download Practice Questions on Chapter 3 CHEMA1301 2014

Practice Questions
Chapter 3
Stoichiometry
Circle the correct answer:
1) 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
2) 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
3) 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
4) 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 g/mol, N = 14.0 g/mol)
A) 21.5 g
B) 0.767 g
C) 64.4 g
D) 0.027 g
E) 193.2 g
5) How many moles of H3PO4 are produced when 20.0 g of HCl are produced by the
reaction
PCl5 + 4 H2O → H3PO4 + 5 HCl?
A) (20.0/36.5) g
B) (20.0/35.5)/5 g
C) (20.0/36.5)/5 g
D) (20.0/98.0) g
E) (20.0/98.0)/5 g
6) For the reaction 2 Al + Fe2O3 → Al2O3 + 2 Fe, 2.5 g of Al (27.0 g/mol) and 7.2 g
1
of Fe2O3 (159.8 g/mol) produce how many g of Fe (55.9 g/mol)?
A) 2.5 (55.9/27.0) g
B) 2.5 (55.9)(2)/(27.0)(2) g
C) 7.2 (55.9)(2)/159.8 g
D) 7.2 (55.9/159.8) g
E) 2.5 (55.9/159.8) g
7) 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
8) 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 Cl2 reacts with excess Fe?
A) 3.1 mol
B) 4.6 mol
C) 1.5 mol
D) 2.3 mol
E) 6.9 mol
9) 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
10) 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
11) 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
2
E) 5.23 g CO2, 2.38 g H2O
12) 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
13) Which of the following represents a 1.00 M aqueous solution of glucose
(C6H12O6)?
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
14) 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
15) 45.8 mL of a 3.14 M sodium chloride solution were used to react completely with
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
16) 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
17) 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) mL
B) 14.1(0.024/3.0) mL
C) 14.1(3.0/0.024) mL
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D) (14.1/0.024)/3.0 mL
E) (0.024×3)/14.1 mL
18) 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 initial solution?
A) 3.16(52.5/6.25) M
B) 3.16(6.25/52.5) M
C) (3.16)(52.5)(6.25) M
D) 3.16(52.5/6250) M
E) (6.25)(3.16)/0.0525 M
19) 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) M
B) 6.75 (8.56/6.20) M
C) 6.75 (6200/85.6) M
D) 6.75 (85.6/6200) M
E) 8.56 (6.20/6.75) M
20) 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
21) What mass of trisodium phosphate is required to prepare 250.0 mL of a solution
that 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
22) 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
23) 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
4
D) 310 mL
E) 150 mL
24) 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 g
B) 28.3 g
C) 25.2 g
D) 12.6 g
E) 37.8 g
25) Given the reaction:
2 KMnO4 + 10 KI + 8 H2SO4 → 6 K2SO4 + 2 MnSO4 + 5 I2 + 8 H2O,
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
26) 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 g
B) 38.6 g
C) 101 g
D) 20.6 g
E) 82.5 g
27) 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
28) 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
5
29) The Haber Process for the 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%
30) 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
31) 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 g
B) 2.84 g
C) 7.30 g
D) 4.87 g
E) 3.65 g
32) How much Cl2, in g, is required to produce 12.0 g CCl4 according to the
following reaction?
CH4 + 4 Cl2 → CCl4 + 4 HCl
A) 12.0 g
B) 5.52 g
C) 22.1 g
D) 1.38 g
E) 11.0 g
33) 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) 27.3 g
C) 10.7 g
D) 21.4 g
E) 31.8 g
34) 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
6
C3H8/C4H10 = 1.33?
A) 3.9 g
B) 11 g
C) 14 g
D) 21 g
E) 27 g
35) 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
36) What is the molarity of methanol, CH3OH (d = 0792 g/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
37) 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
38) What mass of MgCl2 in grams must be added to 250.0 mL of a 0.25 M MgCl2
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
39) 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
40) The chemical reaction occurring during the discharge of a lead storage battery can
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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 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
41) 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%
42) 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%
43) 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
44) 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%
8
45) 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 g
B) 41.7 g
C) 125 g
D) 186 g
E) 20.2 g
46) 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 g
B) 243 g
C) 62.6 g
D) 48.8 g
E) 205 g
47) 0.400 mole of sucrose, C12H22O11, contains ________ moles of C.
A) 12
B) 6.02 x 1023
C) 5.02 x 1022
D) 2.89 x 1024
E) 4.80
48) How many moles of carbon atoms are there in 0.500 mole of C2H6?
A) 0.500 mole
B) 1.00 mole
C) 3.00 moles
D) 6.02 x 1023 moles
E) 4.00 moles
49) What is the molar mass of copper(II) sulfate, CuSO4?
A) 16.00 g
B) 63.60 g
C) 111.6 g
D) 159.6 g
E) 319.2 g
50) Calculate the molar mass of magnesium chloride, MgCl2.
A) 24.3 g
B) 95.3 g
C) 125.9 g
9
D) 59.8 g
E) 70.0 g
51) What is the molar mass of sodium phosphate, Na3PO4?
A) 119.2 g
B) 308.0 g
C) 164.0 g
D) 226.1 g
E) 354.0 g
52) How many moles of water, H2O, are present in 75.0 g H2O?
A) 4.41 moles
B) 4.17 moles
C) 75.0 moles
D) 7.50 moles
E) 1.35 x 103 moles
53) 0.100 mole of lithium weighs
A) 3.00 g.
B) 0.300 g.
C) 6.94 g.
D) 0.694 g.
E) 0.700 g.
54) 4.00 moles of sodium have a mass of
A) 4.60 g.
B) 11.0 g.
C) 23.0 g.
D) 44.0 g.
E) 92.0 g.
55) How many moles of K2SO4 are in 15.0 g of K2SO4?
A) 0.172 moles
B) 2.61 x 103 moles
C) 0.111 moles
D) 0.0861 moles
E) 0.119 moles
56) 3.00 moles of NO2 have a mass of
A) 138 g.
B) 46.0 g.
C) 30.0 g.
D) 90.0 g.
E) 45.0 g.
57) How many grams of Fe2O3 are there in 0.500 mole of Fe2O3?
A) 79.8 g
B) 35.9 g
C) 63.8 g
10
D) 51.9 g
E) 160. g
58) 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 + 3 Ca(NO3)2 → Ca3(PO4)2 + 6KNO3
E) K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + KNO3
59) Which of the following correctly gives the best coefficients for the reaction
below?
N2H4 + H2OH2 → N2 + H2O
A) 1, 1, 1, 1
B) 1, 2, 1, 4
C) 2, 4, 2, 8
D) 1, 4, 1, 4
E) 2, 4, 2, 4
60) What coefficient is placed in front of O2 to complete the balancing of the
following equation?
C5H8 + ? O2 → 5 CO2 + 4 H2O
A) 1
B) 3
C) 5
D) 7
E) 9
61) What is the coefficient of hydrogen, H2, when the following equation is
balanced?
Al + H2SO4 → Al2(SO4)3 + ? H2
A) 1
B) 2
C) 3
D) 4
E) 5
Pentane (C5H12) reacts with oxygen (O2) to form carbon dioxide (CO2) and water
(H2O) according to the following reaction. Answer the following question(s) about
11
this reaction.
C5H12 + ? O2 → ? CO2 + ? H2O
62) What is the coefficient for oxygen in the balanced equation?
A) 2
B) 4
C) 5
D) 6
E) 8
63) What is the coefficient for carbon dioxide in the balanced equation?
A) 2
B) 4
C) 5
D) 6
E) 8
64) What is the coefficient for water in the balanced equation?
A) 2
B) 4
C) 5
D) 6
E) 8
65) In this reaction, what is the coefficient for calcium oxide?
CaO + CO2 → CaCO3
A) 1
B) 2
C) 3
D) 4
E) 5
66) In this reaction, what is the correct coefficient for sodium chloride?
Pb(NO3)2 + ? NaCl → PbCl2 + ? NaNO3
A) 1
B) 2
C) 3
D) 4
E) 5
67) In a ________ reaction, two or more elements or compounds form one product.
A) decomposition
B) single replacement
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C) combustion
D) double replacement
E) combination
68) The following reaction is an example of a ________ reaction.
C5H8 + 7O2 → 5CO2 + 4H2O
A) combination
B) single replacement
C) combustion
D) decomposition
E) double replacement
69) The following reaction takes place when an electric current is passed through
water. It is an example of a ________ reaction.
2H2O
2H2 + O2
A) combination
B) single replacement
C) combustion
D) decomposition
E) double replacement
70) What is the classification for this reaction?
SO3 + H2O → H2SO4
A) decomposition
B) combination
C) replacement
D) double replacement
E) combustion
71) Given the following equation, what is the correct form of the conversion factor
needed to convert the number of moles of O2 to the number of moles of Fe2O3
produced?
4Fe + 3O2 → 2Fe2O3
A)
B)
13
C)
D)
E)
For the following question(s), consider the following equation.
2Mg + O2 → 2MgO
72) The number of moles of oxygen gas needed to react with 4.0 moles of Mg is
A) 1.0 mole.
B) 2.0 moles.
C) 3.0 moles.
D) 4.0 moles.
E) 6.0 moles.
73) The number of moles of MgO produced when 0.20 mole of O2 reacts completely
is
A) 0.10 mole.
B) 0.20 mole.
C) 0.40 mole.
D) 0.60 mole.
E) 0.80 mole.
74) How many grams of magnesium are needed to react with 16 g of O2?
A) 0.50 gram
B) 1.0 gram
C) 12 grams
D) 24 grams
E) 48 grams
75) How many grams of MgO are produced when 40.0 grams of O2 react completely
with Mg?
A) 30.4 g
B) 50.4 g
C) 60.8 g
D) 101 g
14
E) 201 g
76) What is the correct form of the conversion factor needed to convert the number of
moles of H2O to the number of moles of NH3 produced?
A)
B)
C)
D)
E)
77) When 2 moles of Mg3N2 are allowed to react, how many moles of H2O also
react?
A) 1 mole
B) 4 moles
C) 6 moles
D) 8 moles
E) 12 moles
78) Chemical equations are balanced in order to obey the law of
A) definite proportions.
B) mass action.
C) mass conservation.
D) multiple proportions.
79) Which one of the following statements about balanced equations is false?
In a balanced reaction
A) atoms must be balanced on both sides of the reaction arrow.
B) mass must be conserved.
C) molecules must be balanced on both sides of the reaction arrow.
D) net charge must be balanced on both sides of the reaction arrow.
15
80) Which one of the following statements about balanced equations is true? A
reaction is balanced by
A) changing the charge on an ion.
B) changing the formula of the molecule.
C) multiplying by suitable coefficients.
D) rearranging atoms in a molecule.
81) What is the stoichiometric coefficient for oxygen when the following equation is
balanced using the lowest whole-number coefficients
_____ C3H8O(l) + _____ O2(g) → _____ CO2(g) + _____ H2O(l)
A) 3
B) 5
C) 7
D) 9
82) 1.00 mole of O2 contains the same number of molecules as
A) 0.667 mole of O3.
B) 1.00 mole of CH3CO2H.
C) 2.00 mole of CH3CH2OH.
D) All of these
83) 1.00 mole of O2 contains the same number of oxygen atoms as
A) 0.667 mole of O3.
B) 1.00 mole of CH3CO2H.
C) 2.00 mole of CH3CH2OH.
D) All of the above
84) How many iron(II) ions, Fe2+ are there in 5.00 g of FeSO4?
A) 5.46 × 10-26 iron (II) ions
B) 1.98 × 1022 iron (II) ions
C) 1.83 × 1025 iron (II) ions
D) 4.58 × 1026 iron (II) ions
85) What is the mass of 8.50 × 1022 molecules of NH3?
A) 0.00830 g
B) 0.417 g
C) 2.40 g
D) 120 g
86) What mass of dinitrogen monoxide, N2O, contains the same number of molecules
as 3.00 g of trichlorofluoromethane, CCl3F?
A) 0.106 g
B) 0.961 g
C) 1.04 g
D) 9.37 g
16
87) What mass of sulfur hexafluoride, SF6, has the same number of fluorine atoms as
25.0 g of oxygen difluoride, OF2?
A) 0.901 g
B) 8.33 g
C) 22.5 g
D) 203 g
88) Balance the chemical equation given below, and determine the number of moles
of iodine that reacts with 10.0 g of aluminum.
_____ Al(s) + _____ I2(s) → _____ Al2I6(s)
A) 0.247 mol
B) 0.556 mol
C) 0.741 mol
D) 1.11 mol
89) Balance the chemical equation given below, and determine the number of grams
of MgO needed to produce 15.0 g of Fe2O3.
_____ MgO(s) + _____ Fe(s) → _____ Fe2O3(s) + _____ Mg(s)
A) 0.0877 g
B) 1.26 g
C) 3.78 g
D) 11.4 g
90) Dinitrogen monoxide gas decomposes to form nitrogen gas and oxygen gas. How
many grams of oxygen are formed when 5.00 g of dinitrogen monoxide decomposes?
A) 0.550 g
B) 1.82 g
C) 3.64 g
D) 7.27 g
91) If the percent yield for the following reaction is 65.0%, how many grams of
KClO3 are needed to produce 42.0 g of O2?
2 KClO3(s) → 2 KCl(s) + 3 O2(g)
A) 69.7 g
B) 107 g
C) 165 g
D) 371 g
92) Which of the following statements is false concerning the formula of a
compound?
A) The empirical formula is the simplest whole numbered ratio of atoms in a
compound.
B) The molecular formula is the true ratio of atoms in a compound.
C) The molecular formula and empirical formula can be identical.
D) The number of atoms in a molecular formula is always greater than the number of
atoms in an empirical formula.
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93) What is the empirical formula for ethyl fluoride if the compound contains 49.97%
carbon, 10.51% hydrogen, and 39.52% fluorine by mass?
A) C2H5F
B) C4H10F2
C) C4H10F4
D) C25F2
94) What is the empirical formula for perfluoropropane if the compound contains
81% fluorine and 19% carbon by mass?
A) CF3
B) C2F8
C) C3F8
D) C19F81
95) What is the empirical formula of a substance that contains 2.64 g of C, 0.444 g of
H, and 3.52 g of O?
A) CH2O
B) C2H4O2
C) C2H4O3
D) C3H4O4
96) Which one of the following is not an empirical formula?
A) CHO
B) CH2O
C) C2H4O
D) C2H4O2
97) Which one of the following is an empirical formula?
A) C2F6
B) H2SO4
C) N2H4
D) P4O10
98) A compound responsible for the odor of garlic has a molecular weight of 146
g/mol. A 0.650 g sample of the compound contains 0.321 g of carbon, 0.044 g of
hydrogen, and 0.285 g of sulfur. What is the molecular formula of the compound?
A) CH5S
B) C3H5S
C) C3H15S3
D) C6H10S2
99) In the combustion analysis of an unknown compound containing only carbon,
hydrogen, and oxygen, the grams of oxygen are found from the grams of
A) CO2 only.
B) H2O only.
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C) CO2 and H2O only.
D) CO2, H2O and unknown compound.
100) Combustion analysis of an unknown compound containing only carbon and
hydrogen produced 4.554 g of CO2 and 2.322 g of H2O. What is the empirical
formula of the compound?
A) CH2
B) C2H5
C) C4H10
D) C5H2
101) Combustion analysis of 2.400 g of an unknown compound containing carbon,
hydrogen, and oxygen produced 4.171 g of CO2 and 2.268 g of H2O. What is the
empirical formula of the compound?
A) C2H5O
B) C2H5O2
C) C2H10O3
D) C3H8O2
102) Combustion analysis of a 0.675 g sample of an unknown compound that contains
only carbon, hydrogen, and oxygen gives 0.627 g of CO2 and 1.534 g of H2O. The
molecular mass of the unknown is
A) C3H6O.
B) C6H12O2.
C) C9H18O3.
D) unable to be determined from this data.
103) Isoeugenol is the compound which gives the characteristic odor to nutmeg and
contains carbon, hydrogen, and oxygen. If a 0.500 g sample of isoeugenol is
combusted it gives 1.341 g of CO2 and 0.329 g of H2O. Isoeugenol has a molecular
weight of 164 g/mol. What is the molecular formula of isoeugenol?
A) C2HO
B) C5H6O
C) C8H4O4
D) C10H12O2
104) 7.0 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia
according to the chemical equation shown below. Which one of the following
statements is false?
N2(g) + 3 H2(g) → 2 NH3(g)
A) 3.5 g of hydrogen are left over.
B) Hydrogen is the excess reactant.
C) Nitrogen is the limiting reactant.
D) The theoretical yield of ammonia is 15 g.
105) 5.0 g of iron is reacted with 5.0 g of water according to the chemical equation
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shown below.
Which one of the following statements is false?
3 Fe(s) + 4 H2O(l) → Fe3O4(s) + 4 H2(g)
A) 6.91 g of Fe3O4 are produced.
B) 2.85 g of H2O are left over.
C) Mass is conserved in this reaction.
D) Water is the limiting reactant.
106) If the percent yield for the following reaction is 75.0%, and 45.0 g of NO2 are
consumed in the reaction, how many grams of nitric acid, HNO3(aq), are produced?
3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g)
A) 30.8 g
B) 41.1 g
C) 54.8 g
D) 69.3 g
107) Molarity is defined as
A) moles of solute per liter of solution.
B) moles of solute per liter of solvent.
C) moles of solvent per liter of solution.
D) moles of solvent per liter of solvent.
108) What is the concentration of FeCl3 in a solution prepared by dissolving 10.0 g of
FeCl3 in enough water to make 275 mL of solution?
A) 2.24 × 10-4 M
B) 0.224 M
C) 4.46 M
D) 4.46 × 103 M
109) How many grams of AgNO3 are needed to make 250. mL of a solution that is
0.135 M?
A) 0.0917 g
B) 0.174 g
C) 5.73 g
D) 9.17 g
110) What volume of a 0.540 M NaOH solution contains 15.5 g of NaOH?
A) 0.209 L
B) 0.718 L
C) 1.39 L
D) 4.78 L
111) What is the concentration of NO3- ions in a solution prepared by dissolving 15.0
g of Ca(NO3)2 in enough water to produce 300. mL of solution?
A) 0.152 M
B) 0.305 M
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C) 0.403 M
D) 0.609 M
112) Which substance is the limiting reactant when 2.0 g of sulfur reacts with 3.0 g
of oxygen and 4.0 g of sodium hydroxide according to the following chemical
equation:
2 S(s) + 3 O2(g) + 4 NaOH(aq) → 2 Na2SO4(aq) + 2 H2O(l)
A) S(s)
B) O2(g)
C) NaOH(aq)
D) None of these substances is the limiting reactant.
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