17) Which of the following has the greatest mass?
A) 3.88 × 1022 molecules of O2
B) 1.00 g of O2
C) 0. 0312 mol of O2
D) All of these have the same mass.
18) Which of the following has the smallest mass?
A) 3.50 × 1023 molecules of I2
B) 85.0 g of Cl2
C) 2.50 mol of F2
D) 0. 050 kg of Br2
19) How many moles of CuO can be produced from 0.900 mol of Cu2O in the following reaction?
2 Cu2O(s) + O2(g) → 4 CuO(s)
A) 0.450 mol
B) 0.900 mol
C) 1.80 mol
D) 3.60 mol
20) How many moles of BCl3 are needed to produce 10.0 g of HCl(aq) in the following reaction?
BCl3(g) + 3 H2O(l) → 3 HCl(aq) + B(OH)3(aq)
A) 0. 0914 mol
B) 0. 274 mol
C) 0.823 mol
D) 10.9 mol
21) How many grams of calcium chloride are needed to produce 1.50 g of potassium chloride?
CaCl2(aq) + K2CO3(aq) → 2 KCl(aq) + CaCO3(aq)
A) 0.896 g
B) 1.12 g
C) 2.23 g
D) 4.47 g
22) Balance the chemical equation given below, and determine the number of moles of iodine that reacts
with 30.0 g of aluminum.
_____ Al(s) + _____ I2(s) → _____ Al2I6(s)
A) 0.741 mol
B) 1.67 mol
C) 2.22 mol
D) 3.33 mol
23) Balance the chemical equation given below, and determine the number of grams of MgO are needed
to produce 10.0 g of Fe2O3.
_____ MgO(s) + _____ Fe(s) → _____ Fe2O3(s) + _____ Mg(s)
A) 0.312 g
B) 0.841 g
C) 2.52 g
D) 7.57 g
24) Dinitrogen monoxide gas decomposes to form nitrogen gas and oxygen gas. How many grams of
oxygen are formed when 10.0 g of dinitrogen monoxide decomposes?
A) 0. 275 g
B) 3.64 g
C) 7.27 g
D) 14.5 g
25) If the density of ethanol, C2H5OH, is 0.789 g/mL. How many milliliters of ethanol are needed to
produce 15.0 g of CO2 according to the following chemical equation?
C2H5OH(l) + 3 O2(g) → 2 CO2(g) + 3 H2O(l)
A) 6.19 mL
B) 9.95 mL
C) 19.9 mL
D) 39.8 mL
26) When 11.0 g of calcium metal is reacted with water, 5.00 g of calcium hydroxide is produced.
Using the following balanced equation, calculate the percent yield for the reaction?
Ca(s) + 2 H2O(l) → Ca(OH)2(aq) + H2(g)
A) 12.3%
B) 24.6%
C) 45.5%
D) 84.0%
27) If the percent yield for the following reaction is 65.0%, how many grams of KClO3 are needed to
produce 32.0 g of O2?
2 KClO3(s) → 2 KCl(s) + 3 O2(g)
A) 53.1 g
B) 81.7 g
C) 126 g
D) 283 g
28) 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
29) 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.
30) 5.0 g of iron is reacted with 5.0 g of water according to the chemical equation 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.
31) 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.
32) When 7.00 × 1022 molecules of ammonia react with 6.00 × 1022 molecules of oxygen according to
the chemical equation shown below, how many grams of nitrogen gas are produced?
4 NH3(g) + 3 O2(g) → 2 N2(g) + 6 H2O(g)
A) 1.63 g
B) 1.86 g
C) 4.19 g
D) 6.51 g
33) When silver nitrate reacts with barium chloride, silver chloride and barium nitrate are formed. How
many grams of silver chloride are formed when 10.0 g of silver nitrate reacts with 15.0 g of barium
chloride?
A) 8.44 g
B) 9.40 g
C) 11.9 g
D) 18.8 g
34) Balance the chemical equation given below, and calculate the volume of nitrogen monoxide gas
produced when 8.00 g of ammonia is reacted with 12.0 g of oxygen at 25°C? The density of nitrogen
monoxide at 25°C is 1.23 g/L.
_____ NH3(g) + _____ O2(g) → _____ NO(g) + _____ H2O(l)
A) 7.32 L
B) 11.1 L
C) 11.5 L
D) 17.3 L
35) What is the concentration of FeCl3 in a solution prepared by dissolving 20.0 g of FeCl3 in enough
water to make 275 mL of solution?
A) 4.48 × 10-4 M
B) 0. 448 M
C) 2.23 M
D) 2.23 × 103 M
36) 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) 91.7 g
37) What volume of a 0.540 M NaOH solution contains 11.5 g of NaOH?
A) 0. 155 L
B) 0. 532 L
C) 1. 88 L
D) 6.44 L
38) What is the concentration of NO3– ions in a solution prepared by dissolving 25.0 g of Ca(NO3)2 in
enough water to produce 300. mL of solution?
A) 0. 254 M
B) 0. 508 M
C) 0. 672 M
D) 1.02 M
39) If the reaction of phosphate ion with water is ignored, what is the total concentration of ions in a
solution prepared by dissolving 3.00 g of K3PO4 in enough water to make 350. mL of solution?
A) 0.0 101 M
B) 0. 0404 M
C) 0. 162 M
D) 0. 323 M
40) What is the concentration of an AlCl3 solution if 150. mL of the solution contains 450. mg of
Cl– ion?
A) 2.82 × 10-2 M
B) 6.75 × 10-2 M
C) 8.46 × 10– 2 M
D) 2.54 × 10-1 M
41) What is the concentration of HCl in the final solution when 65 mL of a 12 M HCl solution is diluted
with pure water to a total volume of 0.15 L?
A) 2.8 × 10– 2 M
B) 5.2 M
C) 28 M
D) 5.2 × 103 M
42) How many milliliters of a 9.0 M H2SO4 solution are needed to make 0. 35 L of a 3.5 M solution?
A) 0. 14 mL
B) 0.90 mL
C) 140 mL
D) 900 mL
43) A FeCl3 solution is 0.175 M. How many mL of a 0.175 M FeCl3 solution are needed to make
450. mL of a solution that is 0.300 M in Cl– ion?
A) 0.771 mL
B) 257 mL
C) 771 mL
D) It is not possible to make a more concentrated solution from a less concentrated solution.
44) A student dissolved 4.00 g of Co(NO3)2 in enough water to make 100. mL of stock solution.
He took 4.00 mL of the stock solution and then diluted it with water to give 275. mL of a final solution.
How many grams of NO3– ion are there in the final solution?
A) 0.0 197 g
B) 0.0 394 g
C) 0.0 542 g
D) 0. 108 g
45) A student prepared a stock solution by dissolving 10.0 g of KOH in enough water to make 150. mL
of solution. She then took 15.0 mL of the stock solution and diluted it with enough water to make water
to make 65.0 mL of a final solution. What is the concentration of KOH for the final solution?
A) 0. 274 M
B) 0. 356 M
C) 2.81 M
D) 3.65 M
46) How many milliliters of 0.260 M Na2S are needed to react with 40.00 mL of 0.315 M AgNO3?
Na2S(aq) + 2 AgNO3(aq) → 2 NaNO3(aq) + Ag2S(s)
A) 24.2 mL
B) 48.5 mL
C) 66.0 mL
D) 96.9 mL
47) How many grams of CaCl2 are formed when 15.00 mL of 0.00237 M Ca(OH)2 reacts with excess
Cl2 gas?
2 Ca(OH)2(aq) + 2 Cl2(g) → Ca(OCl)2(aq) + CaCl2(s) + 2 H2O(l)
A) 0.00 197 g
B) 0.00 394 g
C) 0.0 0789 g
D) 0.0 507 g
48) When 31.2 mL of 0.500 M AgNO3 is added to 25.0 mL of 0.300 M NH4Cl, how many grams of
AgCl are formed?
AgNO3(aq) + NH4Cl(aq) → AgCl(s) + NH4NO3(aq)
A) 1.07 g
B) 2.24 g
C) 3.31 g
D) 6.44 g
49) How many milliliters of 0.200 M FeCl3 are needed to react with an excess of Na2S to produce
1.38 g of Fe2S3 if the percent yield for the reaction is 65.0%?
3 Na2S(aq) + 2 FeCl3(aq) → Fe2S3(s) + 6 NaCl(aq)
A) 25.5 mL
B) 43.1 mL
C) 51.1 mL
D) 102 mL
50) If 100. mL of 0.400 M Na2SO4 is added to 200. mL of 0.600 M NaCl, what is the concentration of
Na+ ions in the final solution? Assume that the volumes are additive.
A) 0.534 M
B) 0.667 M
C) 1.00 M
D) 1.40 M
51) How many milliliters of 0.550 M hydriodic acid are needed to react with 15.00 mL of 0.217 M
CsOH?
HI(aq) + CsOH(aq) → CsI(aq) + H2O(l)
A) 0. 0263 mL
B) 0.169 mL
C) 5.92 mL
D) 38.0 mL
52) In an acid-base neutralization reaction 38.74 mL of 0.500 M potassium hydroxide reacts with
50.00 mL of sulfuric acid solution. What is the concentration of the H2SO4 solution?
A) 0. 194 M
B) 0. 387 M
C) 0. 775 M
D) 1.29 M
53) Balance the chemical equation given below, and determine the number of milliliters of 0.00300 M
phosphoric acid required to neutralize 45.00 mL of 0.00150 M calcium hydroxide.
_____ Ca(OH)2(aq) + _____ H3PO4(aq) → _____ Ca3(PO4)2(aq) + _____ H2O(l)
A) 3.04 mL
B) 15.0 mL
C) 22.5 mL
D) 33.8 mL
54) When 280. mL of 1.50 × 10-4 M hydrochloric acid is added to 125 mL of 1.75 × 10-4 M Mg(OH)2,
the resulting solution will be
A) acidic.
B) basic
C) neutral.
D) It is impossible to tell from the information given.
55) Which one of the following contains 39% carbon by mass?
A) C2H2
B) CH4
C) CH3NH2
D) CO2
56) 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
57) Which one of the following is not an empirical formula?
A) CHO
B) CH2O
C) C2H4O
D) C2H4O2
58) Combustion analysis of an unknown compound containing only carbon and hydrogen produced
0.2845 g of CO2 and 0.1451 g of H2O. What is the empirical formula of the compound?
A) CH2
B) C4H5
C) C4H10
D) C5H2
59) Combustion analysis of 1.200 g of an unknown compound containing carbon, hydrogen, and
oxygen produced 2.086 g of CO2 and 1.134 g of H2O. What is the empirical formula of the
compound?
A) C2H5O
B) C2H5O2
C) C2H10O3
D) C3H8O2
3.3 Short Answer Questions
1) A balanced equation has the same numbers and kinds of ________ on both sides of the reaction
arrow.
2) When the reaction C4H10 + O2 → CO2 + H2O is balanced using the smallest whole number
coefficients, the coefficient in front of O2 is ________.
3) When the reaction C3H8 + O2 → CO2 + H2O is balanced, the total number of oxygen atoms in the
balanced equation is ________.
4) The fundamental SI unit for measuring matter is the ________.
5) To the nearest whole number, the molar mass of Cu(NO3)2 is ________ g/mol.
6) The number of grams in 0.333 mol of urea, (NH2)2CO, is ________.
7) How many moles are in 7.8 g of acetamide, CH3CONH2?
8) The balanced equation for the gaseous state oxidation of ammonia is shown below.
4 NH3 + 5 O2 → 4 NO + 6 H2O
How many moles of O2 are required to react with 1.2 mole of NH3?
9) The balanced equation for the reaction of acetylene, C2H2, and oxygen in an acetylene torch is
2 C2H2 + 5 O2 → 4 CO2 + 2 H2O.
In this reaction the number of grams of oxygen required to react with 0.13 g of acetylene is ________.
10) Ozone is unstable, decomposing to dioxygen, as shown in the balanced equation
2 O3 → 3 O2.
In this reaction, how many grams of dioxygen can be formed from the decomposition of 96 grams of
ozone?
11) The balanced equation for the decomposition of water is shown below.
2 H2O → 2 H2 + O2
If 0.72 g of water react completely in this reaction, what is the theoretical yield of H2?
12) Oxygen can be produced from the catalytic decomposition of KClO3 as shown in the balanced
equation below.
2 KClO3 → 2 KCl + 3 O2
What is the percent yield if 3.20 grams of oxygen are formed from the reaction of 12.3 grams of
KClO3?
13) If 4.0 g of H2 react with 4.0 g of F2 in the reaction shown below, what is the limiting reactant?
H2 + F2 → 2 HF
14) Ozone reacts with iodide ion as shown in the balanced equation below.
O3 + 2 I– + H2O → O2 + I2 + 2 OH–
In this reaction, how many grams of dioxygen can be formed from the reaction of 96 grams of ozone?
15) When carbon dioxide dissolves in water, H+ is formed, which makes the solution acidic, as shown in
the balanced equation below.
CO2 + H2O → HCO3– + H+
What is the percent yield if 0.0088 g of CO2 reacts with 900 g of H2O to form 0.000108 g of H+?
16) Hydrazine, N2H4, is used as a rocket fuel. In the reaction below, if 80.1 g of N2H4 and 92.0 g of
N2O4 are allowed to react, which is the limiting reactant, and how many grams of excess reactant
remain at the end of the reaction?
2 N2H4 + N2O4 → 3 N2 + 4 H2O
17) What is the molarity of a solution prepared by dissolving 0.80 g of NaOH in enough water to make
250 mL of solution?
18) The number of moles of CaCl2 in 25.0 mL of 0.222 M CaCl2 is ________.
19) The number of grams of NaCl required to prepare 500 mL of 0.100 M NaCl is ________.
20) The number of milliliters of 12.0 M HCl required to prepare 250 mL of 0.500 M HCl is ________.
21) What is the molarity of a solution prepared by diluting 25 mL of 2.0 M HCl with enough water to
make 250 mL of solution?
22) The number of milliliters of 0.250 M HCl required to react with 50.00 mL of 0.450 M KOH in the
reaction shown below is ________.
HCl + KOH → H2O + KCl
23) What is the empirical formula of benzene, C6H6?
24) The empirical formula of a compound that contains 82.66% carbon and 17.34% hydrogen is
________.
25) Analysis of a 1.000-g sample of the oral hypoglycemic agent metforminTM yielded 0.3720 g
of carbon, 0.0858 g of hydrogen, and 0.5422 g of nitrogen. MetforminTM has a molar mass of
129.16 g/mol. What is the molar mass of MetforminTM?