62) Pentacarbonyliron (Fe(CO)5) reacts with phosphorous trifluoride (PF3) and hydrogen, releasing
carbon monoxide:
Fe(CO)5 + PF3 + H2 → Fe(CO)2(PF3)2(H)2 + CO (not balanced)
The reaction of 5.0 mol of Fe(CO)5, 8.0 mol of PF3and 6.0 mol of H2 will release __________ mol of
CO.
A) 15
B) 5.0
C) 24
D) 6.0
E) 12
63) What is the maximum mass in grams of NH3 that can be produced by the reaction of 1.0 g of N2
with 3.0 g of H2 via the equation below?
N2 (g) + H2 (g) → NH3 (g) (not balanced)
A) 2.0
B) 1.2
C) 0.61
D) 17
E) 4.0
64) What is the maximum amount in grams of SO3 that can be produced by the reaction of 1.0 g of S
with 1.0 g of O2 via the equation below?
S (s) + O2 (g) → SO3 (g) (not balanced)
A) 0.27
B) 1.7
C) 2.5
D) 3.8
E) 2.0
65) Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide:
4Al (s) + 3 O2 (g) → 2 Al2O3 (s)
The maximum amount of Al2O3 that can be produced from 2.5 g of Al and 2.5 g of O2 is __________
g.
A) 9.4
B) 7.4
C) 4.7
D) 5.3
E) 5.0
66) Sulfur and fluorine react in a combination reaction to produce sulfur hexafluoride:
S (s) + 3 F3 (g) → SF6 (g)
The maximum amount of SF6 that can be produced from the reaction of 3.5 g of sulfur with 4.5 g of
fluorine is __________ g.
A) 12
B) 3.2
C) 5.8
D) 16
E) 8.0
67) Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide:
4Al (s) + 3 O2 (g) → 2 Al2O3 (s)
In a particular experiment, the reaction of 2.5 g of Al with 2.5 g of O2 produced 3.5 g of Al2O3. The %
yield of the reaction is __________.
A) 74
B) 37
C) 47
D) 66
E) 26
68) Sulfur and oxygen react in a combination reaction to produce sulfur trioxide, an environmental
pollutant:
2S (s) + 3O2 (g) → 2SO3 (g)
In a particular experiment, the reaction of 1.0 g S with 1.0 g O2 produced 0.80 g of SO3. The % yield in
this experiment is __________.
A) 30
B) 29
C) 21
D) 88
E) 48
69) Sulfur and fluorine react in a combination reaction to produce sulfur hexafluoride:
S (s) + 3F2 (g) → SF6 (g)
In a particular experiment, the percent yield is 79.0%. This means that in this experiment, a 7.90-g
sample of fluorine yields __________ g of SF6.
A) 30.3
B) 10.1
C) 7.99
D) 24.0
E) 0.110
3.3 Algorithmic Questions
1) The molecular weight of acetic acid ( HC2H3O2), the acid in vinegar, is __________ amu (rounded
to one decimal place).
A) 59.0
B) 29.0
C) 60.1
D) 8.0
E) 32.0
2) Determine the mass percent (to the hundredths place) of Na in sodium bicarbonate (NaHCO3).
3) There are __________ mol of carbon atoms in 3 mol of dimethylsulfoxide (C2H6SO).
A) 2
B) 4
C) 6
D) 8
E) 10
4) How many grams of hydrogen are in 23 g of CH4O?
A) 2.9
B) 4.6
C) 2.3
D) 4.0
E) 5.8
5) How many grams of oxygen are in 45 g of C2H2O2?
A) 8.3
B) 9.3
C) 17
D) 25
E) 31
6) A 3.92-g sample of magnesium nitrate, Mg(NO3)2, contains __________ mol of this compound.
A) 2.32
B) 1.65
C) 0.111
D) 0.0529
E) 0.0264
7) A 17.6-g sample of ammonium carbonate contains __________ mol of ammonium ions.
A) 0.366
B) 0.183
C) 0.176
D) 2.14
E) 3.47
8) What is the empirical formula of a compound that is 52.1% C, 13.1% H, and 34.7% O by mass?
A) C2HO
B) C2HO3
C) C4H12O2
D) C4H13O2
E) C2H6O
9) A certain alcohol contains only three elements, carbon, hydrogen, and oxygen. Combustion of a 30.00
gram sample of the alcohol produced 57.30 grams of CO2 and 35.22 grams of H2O. What is the
empirical formula of the alcohol?
10) Lithium and nitrogen react to produce lithium nitride:
6Li (s) + N2 (g) → 2Li3N (s)
How many moles of N2 are needed to react with 0.710 mol of lithium?
A) 4.26
B) 0.710
C) 0.237
D) 2.13
E) 0.118
11) The combustion of propane (C3H8) produces CO2 and H2O:
C3H8 (g) + 5 O2 (g) → 3CO2 (g) + 4 H2O (g)
The reaction of 5.5 mol of O2 will produce __________ mol of H2O.
A) 5.5
B) 5.0
C) 2.0
D) 4.4
E) 1.0
12) Magnesium and nitrogen react in a combination reaction to produce magnesium nitride:
3 Mg + N2 → Mg3N2
In a particular experiment, a 10.1-g sample of N2 reacts completely. The mass of Mg consumed is
__________ g.
A) 8.76
B) 26.3
C) 35.1
D) 0.92
E) 13.9
13) The combustion of ammonia in the presence of excess oxygen yields NO2 and H2O:
4 NH3 (g) + 7 O2 (g) → 4 NO2 (g) + 6 H2O (g)
The combustion of 57.6 g of ammonia consumes __________ g of oxygen.
A) 27.0
B) 28.8
C) 54.1
D) 189
E) 94.6
14) Lithium and nitrogen react to produce lithium nitride:
6Li (s) + N2 (g) → 2Li3N (s)
How many moles of lithium nitride are produced when 0.400 mol of lithium react in this fashion?
A) 0.133
B) 0.800
C) 0.0667
D) 1.20
E) 0.200
15) Lithium and nitrogen react in a combination reaction to produce lithium nitride:
6Li (s) + N2 (g) → 2Li3N (s)
How many moles of lithium are needed to produce 0.20 mol of Li3N when the reaction is carried out in
the presence of excess nitrogen?
A) 0.10
B) 0.60
C) 0.067
D) 0.13
E) 1.2
16) Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements:
2NaN3 (s) → 2Na (s) + 3N2 (g)
How many moles of H2 are produced by the decomposition of 3.55 mol of sodium azide?
A) 2.37
B) 10.7
C) 5.33
D) 1.18
E) 1.78
17) Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements:
2NaN3 (s) → 2Na (s) + 3N2 (g)
How many grams of sodium azide are required to produce 30.5 g of nitrogen?
A) 1.63
B) 0.726
C) 70.8
D) 47.2
E) 106.2
18) Magnesium burns in air with a dazzling brilliance to produce magnesium oxide:
2Mg (s) + O2 (g) → 2MgO (s)
How many moles of O2 are consumed when 4.11 mol of magnesium burns?
A) 0.169
B) 0.487
C) 4.11
D) 8.22
E) 2.06
19) Calcium carbide (CaC2) reacts with water to produce acetylene (C2H2):
CaC2 (s) + 2 H2O (g) → Ca(OH)2 (s) + C2H2 (g)
Production of 3.3 g of C2H2 requires consumption of __________ g of H2O.
A) 1.2
B) 2.3
C) 4.6
D) 480
E) 0.048
20) Lead (II) carbonate decomposes to give lead (II) oxide and carbon dioxide:
PbCO3 (s) → PbO (s) + CO2 (g)
__________ grams of lead (II) oxide will be produced by the decomposition of 7.50 g of lead (II)
carbonate?
A) 0.41
B) 2.50
C) 0.00936
D) 6.26
E) 7.83
21) Lithium and nitrogen react in a combination reaction to produce lithium nitride:
6Li (s) + N2 (g) → 2Li3N (s)
In a particular experiment, 5.50-g samples of each reagent are reacted. The theoretical yield of lithium
nitride is __________ g.
A) 5.53
B) 4.60
C) 27.6
D) 9.20
E) 13.7
22) Magnesium burns in air with a dazzling brilliance to produce magnesium oxide:
2Mg (s) + O2 (g) → 2MgO (s)
When 2.00 g of magnesium burns, the theoretical yield of magnesium oxide is __________ g.
A) 2.00
B) 3.32
C) 0.0823
D) 1.66
E) 6.63
23) Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide:
CaO (s) + H2O (l) → Ca(OH)2 (s)
A 4.00-g sample of CaO is reacted with 3.86 g of H2O. How many grams of water remains after
completion of reaction?
A) 0.00
B) 0.00793
C) 2.57
D) 1.04
E) 0.143
24) If 2352 grams of FeS2 is allowed to react with 1408 grams of O2 according to the following
equation, how many grams of Fe2O3 are produced?
FeS2 + O2 → Fe2O3 + SO2
25) Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide:
CaO (s) + H2O (l) → Ca(OH)2 (s)
In a particular experiment, a 1.50-g sample of CaO is reacted with excess water and 1.48 g of Ca(OH)2
is recovered. What is the percent yield in this experiment?
A) 99
B) 0.99
C) 2.16
D) 74.8
E) 101.2
3.4 Short Answer Questions
1) Complete and balance the following reaction, given that elemental rubidium reacts with elemental
sulfur to form Rb2S (s).
Na (s) + S (s) → __________
2) A compound was found to contain 90.6% lead (Pb) and 9.4% oxygen. The empirical formula for this
compound is __________.
3) The combustion of propane (C3H8 ) in the presence of excess oxygen yields CO2 and H2O:
C3H8 (g) + 5O2 (g) → 3CO2 (g) + 4 H2O (g)
When 7.3 g of C3H8 burns in the presence of excess O2, __________ g of CO2 is produced.
4) Under appropriate conditions, nitrogen and hydrogen undergo a combination reaction to yield
ammonia:
N2 (g) + 3 H2 (g) → 2NH3 (g)
A 9.3-g sample of hydrogen requires __________ g of N2 for a complete reaction.
5) Water can be formed from the stoichiometric reaction of hydrogen with oxygen:
2 H2 (g) + O2 (g) → 2 H2O (g)
A complete reaction of 5.0 g of O2 with excess hydrogen produces __________ g of H2O.
6) The combustion of carbon disulfide in the presence of excess oxygen yields carbon dioxide and sulfur
dioxide:
CS2 (g) + 3O2 (g) → CO2 (g) + 2SO2 (g)
The combustion of 15 g of CS2 in the presence of excess oxygen yields __________ g of SO2.
3.5 True/False Questions
1) The mass of a single atom of an element (in amu) is numerically EQUAL to the mass in grams of 1
mole of that element.
2) The molecular weight is ALWAYS a whole-number multiple of the empirical formula weight.
3) A great deal of the carbon dioxide produced by the combustion of fossil fuels is absorbed into the
oceans.
4) The quantity of product that is calculated to form when all of the limiting reagent reacts is called the
actual yield.