Chapter 12:
Stoichiometry
Practice Test
1.
What mass of SrF2 can be prepared from the reaction of 10.0 g Sr(OH)
2
with excess HF?
Sr(OH)
2
+ 2HF
SrF
2
+ 2H
2
O
a.
10.0 g
b.
9.82 g
c.
9.67 g
d.
10.3 g
Hint
2.
Balance the following equation with the smallest whole-number coefficients. What is the coefficient for H
2
O in this equation?
a.
3
b.
4
c.
2
d.
1
Hint
3.
What is the ratio between the coefficients of any two substances in a balanced equation?
a.
quadratic equation
b.
molar mass balanced equation
c.
chemical formula
d.
mole ratio
Hint
4.
What is the first thing you must do to solve a stoichiometric problem?
a.
Find the limiting reactant.
b.
Find the empirical formula.
c.
Write a balanced chemical equation.
d.
Find the excess reactant.
Hint
5.
How many grams of O
2
are required to burn 18 g C
5
H
12
?
C
5
H
12
+ 8O
2
5CO
2
+ 6H
2
O
a.
64 g
b.
80 g
c.
16 g
d.
32 g
Hint
6.
How many moles of HCl will just react with 0.424 g Ba(OH)
2
?
2HCl + Ba(OH)
2
BaCl
2
+ 2H
2
O
a.
2.48 × 10
3
mol
b.
9.90 × 10
3
mol
c.
1.24 ×10
3
mol
d.
4.94 × 10
3
mol
Hint
7.
What is the percent yield of CO
2
if a reaction using 10.0 g CO with excess O
2
produces 12.8 g CO
2
?
2CO + O
2
2CO
2
a.
76.40%
b.
84.40%
c.
78.10%
d.
81.50%
Hint
8.
Balance the following equation with the smallest whole-number coefficients. How many moles of Ag
2
S can be prepared from 3 moles of Ag? Ag + H
2
S + O
2
Ag
2
S + H
2
O
a.
1.5 mol
b.
4.0 mol
c.
1.0 mol
d.
2.0 mol
Hint
9.
What is the percent yield for the reaction between 9.8 grams of Ca(OH)
2
and 9.8 grams of H
3
PO
4
when 2.5 grams of Ca
3
(PO
4
)
2
are actually obtained?
3Ca(OH)
2
+ 2H
3
PO
4
Ca
3
(PO
4
)
2
+ 6H
2
O
a.
36%
b.
27%
c.
9%
d.
18%
Hint
10.
What is the scientific law that states that matter is not created or destroyed but only transformed in a chemical reaction.
a.
law of gravity
b.
law of conservation of energy
c.
law of conservation of mass
d.
law of conservation of momentum
Hint
11.
In the chemical reaction below, 3.27 grams of Zn are reacted with 3.30 grams of HCl. Which component will limit the reaction?
Zn + 2HCl
ZnCl
2
+ H
2
a.
H
2
b.
HCl
c.
Zn
d.
ZnCl
2
Hint
12.
What do the coefficients in the following balanced chemical equation mean?
2H
+ O
2
2H
2
O
a.
2 moles of oxygen and 1 mole of hydrogen in the products
b.
2 moles of hydrogen and 1 mole of oxygen in the products
c.
2 moles of hydrogen and 1 mole of oxygen in the reactants
d.
2 moles of oxygen and 1 mole of hydrogen in the reactants
Hint
13.
What is the maximum amount of product that can be produced from a given amount of reactant?
a.
theoretical yield
b.
mole ratio
c.
percent yield
d.
actual yield
Hint
14.
If sufficient hydrochloric acid is used to react completely with 48.6 g of magnesium, how much hydrogen will be produced?
2HCl + Mg
MgCl
2
+ H2
a.
6 g
b.
3 g
c.
2 mol
d.
1 mol
Hint
15.
What mass of SrF
2
can be prepared from the reaction of 8.05 g of Sr(OH)
2
with 3.88 g of HF?
Sr(OH)
2
+ 2HF
SrF
2
+ 2H
2
O
a.
12.2 g
b.
11.7 g
c.
8.32 g
d.
10.5 g
Hint
16.
How many grams of Fe
2
O
3
are present in 0.82 mol Fe
2
O
3
?
a.
65 g
b.
130 g
c.
195 g
d.
260 g
Hint
17.
Which reactant in the following reaction is in excess when 9.8 grams of Ca(OH)
2
is reacted with 9.8 grams of H
3
PO
4
?
3Ca(OH)
2
+ 2H
3
PO
4
Ca
3
(PO
4
)
2
+ 6H
2
O
a.
H
3
PO
4
b.
Ca(OH)
2
c.
H
2
O
d.
Ca
3
(PO
4
)
2
Hint
18.
What is the maximum amount of Ca
3
(PO
4
)
2
that can be prepared from 9.8 grams of Ca(OH)
2
and 9.8 grams of H
3
PO
4
?
3Ca(OH)
2
+ 2H
3
PO
4
Ca
3
(PO
4
)
2
+ 6H
2
O
a.
13.4 g
b.
10.3 g
c.
6.8 g
d.
8.6 g
Hint
19.
The reaction of 5.0 grams of fluorine with excess chlorine produced 5.6 grams of ClF3. What percent yield of ClF
3
was obtained?
Cl
2
+ 3F
2
2ClF
3
a.
69%
b.
58%
c.
86%
d.
76%
Hint
20.
What is the balanced chemical equation for the reaction between hydrochloric acid and calcium carbonate when the products of the reaction are calcium chloride, carbon dioxide, and water?
a.
2HCl + CaCl
2
CaCO
3
+ CO
2
+ 2H
2
O
b.
HCl + CaCl
2
CaCO
3
+ CO
2
+ H
2
O
c.
2HCl + CaCO
3
CaCl
2
+ CO
2
+ H
2
O
d.
HCl + CaCO
3
CaCl
2
+ CO
2
+ H
2
O
Hint
