Stoichiometry
Review
Question 1.
Balance the following equation and choose the
quantity which is the sum of the coefficients of the
products.
____ SnS2 + ____ HCl
a)
b)
c)
d)
e)
8
5
3
6
7
___ H2SnCl6 + ____ H2S
Question 1.
Balance the following equation and choose the
quantity which is the sum of the coefficients of the
products.
1 SnS2 + ____
6 HCl
____
a)
b)
c)
d)
e)
8
5
3
6
7
___1H2SnCl6 + ____2H2S
Question 2.
Balance the following equation. What is the
sum of the coefficients of the reactants and
products?
____ CoO + ____ O2
a) 9
b)
c)
d)
e)
3
7
6
8
____ Co2O3
Question 2.
Balance the following equation. What is the
sum of the coefficients of the reactants and
products?
4 CoO + ____
1 O
____
2
a) 9
b)
c)
d)
e)
3
7
6
8
2 Co O
____
2 3
Question 3.
Balance the following equation for the
combustion of octane. What is the sum of the
coefficients of the reactants and products?
____ C8H18 + ____ O2
a)
b)
c)
d)
e)
30
61
52
43
39
____ CO2 + ____ H2O
Question 3.
Balance the following equation for the
combustion of octane. What is the sum of the
coefficients of the reactants and products?
2
25
____ C8H18 + ____ O2
a)
b)
c)
d)
e)
30
61
52
43
39
16
18
____ CO2 + ____ H2O
Question 4.
Calculate the number of moles of N2 produced
from 0.080 moles of NH3 by the following
reaction.
4 NH3 + 6 NO
a)
b)
c)
d)
e)
0.02
0.50
0.08
0.10
0.64
5 N2 + 6 H2O
Question 4.
Calculate the number of moles of N2 produced
from 0.080 moles of NH3 by the following
reaction.
4 NH3 + 6 NO
0.080 mol
a)
b)
c)
d)
e)
0.02
0.50
0.08
0.10
0.64
5 N2 + 6 H2O
? mol
0.080 mol NH3 x 5 moles N2
4 moles NH3
Question 5.
Phosgene was used in WW1 as a war gas. It reacts
with water in the lungs to produce HCl which causes
severe lung damage and ultimately leads to death.
How many grams of HCl are produced when 11.0 g
of CO2 are simultaneously formed?
(C = 12.01, O = 16.00, H = 1.008, Cl = 35.45).
COCl2 + H2O
a) 27.3
b)
c)
d)
e)
36.4
9.11
18.2
0.25
2 HCl + CO2
Question 5.
Phosgene was used in WW1 as a war gas. It reacts
with water in the lungs to produce HCl which causes
severe lung damage and ultimately leads to death.
How many grams of HCl are produced when 11.0 g
of CO2 are simultaneously formed?
(C = 12.01, O = 16.00, H = 1.008, Cl = 35.45).
COCl2 + H2O
2 HCl + CO2
a) 27.3
b)
c)
d)
e)
36.4
9.11
18.2
0.25
11.0 g CO2 x 1 mol CO2 x 2 mol HCl x 36.458 g
44.01 g
1 mol CO2 1 mol
Question 6.
Calculate the number of moles of Na2CS3 produced
from 0.6 moles of CS2 by the following reaction.
3 CS2 + 6 NaOH
a)
b)
c)
d)
e)
0.2
0.4
0.8
0.6
0.9
2 Na2CS3 + Na2CO3 + 3 H2O
Question 6.
Calculate the number of moles of Na2CS3 produced
from 0.6 moles of CS2 by the following reaction.
3 CS2 + 6 NaOH
a)
b)
c)
d)
e)
0.2
0.4
0.8
0.6
0.9
2 Na2CS3 + Na2CO3 + 3 H2O
0.6 mol CS2 x 2 moles N2
3 moles NH3
Question 7.
A sample of lime, CaO, weighing 69 g was
prepared by heating 131 g of limestone, CaCO3.
What was the percent yield of the reaction?
(Atomic weights: Ca = 40.08, C = 12.01, O =
16.00).
CaCO3
a)
b)
c)
d)
e)
97
73
85
94
91
CaO + CO2
Question 7.
A sample of lime, CaO, weighing 69 g was
prepared by heating 131 g of limestone, CaCO3.
What was the percent yield of the reaction?
(Atomic weights: Ca = 40.08, C = 12.01, O =
16.00).
CaCO3
a)
b)
c)
d)
e)
CaO + CO2
97
73
85 131 g CaCO3 x 1 mol CaCO3 x 1 mol CaO x 56.08 g
94
100.09 g
1 mol CaCO3 1 mol
91
= 73.4 g Theoretical yield
% yield =69 g /73.4 g x 100
Question 8.
100. mL of hydrogen gas at STP would contain
how many moles?
a)
b)
c)
d)
e)
0.00446
0.050
0.446
4.46
224
Question 8.
100. mL of hydrogen gas at STP would contain
how many moles?
a)
b)
c)
d)
e)
0.00446
0.050
0.446
4.46
224
100. mL x 1 L x
1000 mL
1 mol
22.4 L
Question 9.
For the reaction:
N2H4 + 3 O2
2 H2O + NO2 + 400 kJ
What is the energy released when 4.60 g if NO2
is produced?
a)
b)
c)
d)
40.0 kJ
18.0 kJ
120.0 kJ
160.0 kJ
Question 9.
For the reaction:
N2H4 + 3 O2
2 H2O + NO2 + 400 kJ
What is the energy released when 4.60 g if NO2
is produced?
a)
b)
c)
d)
40.0 kJ
18.0 kJ
120.0 kJ
160.0 kJ
4.60 g NO2 x 1 mol NO2 x 400 kJ
46.0 g
1 mol NO2
Question 10.
What is the mass of a sample of C3H8 gas of it
occupies 100. mL at STP?
a)
b)
c)
d)
e)
0.196
0.509
5.09
19.6
196
Question 10.
What is the mass of a sample of C3H8 gas of it
occupies 100. mL at STP?
a)
b)
c)
d)
e)
0.196
0.509
5.09
19.6
196
100. mL x 1 L x
1000 mL
1 mol x 44.0 g
22.4 L 1 mol