Stoichiometry
Practice Test
1.
What is the maximum amount of product that can be produced from a given amount of reactant?
a.
mole ratio
b.
percent yield
c.
theoretical yield
d.
actual yield
2.
Balance the following equation with the smallest whole—number coefficients. How many grams of O
2
will be produced if 23.2 g of XeF
2
reacts with excess water?
XeF
2
+H
2
O→Xe+HF+O
2
SC.B.1.4.2
a.
2.19 g
b.
1.10 g
c.
3.31 g
d.
4.42 g
3.
How many grams of Fe
2
O
3
are present in 0.82 mol Fe
2
O
3
?
a.
260 g
b.
195 g
c.
65 g
d.
130 g
4.
The substance that limits the extent of a chemical reaction has a special name. What is this substance called?
a.
excess reactant
b.
limiting product
c.
excess product
d.
limiting reactant
5.
Balance the following equation with the smallest whole—number coefficients. What is the coefficient for O
2
in the balanced equation?
C
5
H
10
+O
2
→ CO
2
+H
2
O
SC.B.1.4.2
a.
10
b.
15
c.
20
d.
5
6.
What is the first thing you must do to solve a stoichiometric problem?
a.
Find the empirical formula.
b.
Find the limiting reactant.
c.
Write a balanced chemical equation.
d.
Find the excess reactant.
7.
Based on the following equation, how many moles of hydrochloric acid are needed to react with 0.64 moles of potassium permanganate?
2KMnO
4
+ 8 HCl → 3 Cl
2
+ 2 MnO
2
+ 4 H
2
O + 2KCl
SC.B.1.4.2
a.
5.1 mol HCl
b.
0.21 mol HCl
c.
2.7 mol HCl
d.
0.64 mol HCl
8.
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
SC.B.1.4.2
a.
81.50%
b.
76.40%
c.
78.10%
d.
84.40%
9.
How many moles of HCl will just react with 0.424 g Ba
OH
2
?
2HCl+Ba
OH
2
→BaCl
2
+2H
2
O
SC.B.1.4.2
a.
4.94 x 10
-3
mol
b.
1.24 x10
-3
mol
c.
9.90 x 10
-3
mol
d.
2.48 x 10
-3
mol
10.
How many moles of sulfur are present in 5 moles of H
2
SO
4
?
a.
5 mol
b.
10 mol
c.
2 mol
d.
1 mol
11.
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
SC.B.1.4.2
a.
Ca
3
PO
4
2
b.
H
2
O
c.
H
3
PO
4
d.
Ca
OH
2
12.
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
SC.B.1.4.2
a.
13 g
b.
6.8 g
c.
10.3 g
d.
8.6 g
13.
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
SC.B.1.4.2
a.
11.7 g
b.
12.2 g
c.
8.32 g
d.
10.5 g
14.
Balance the following equation with the smallest whole-number coefficients. What is the coefficient for H
2
O in this equation?
PBr
3
+H
2
O→H
3
PO
3
+HBr
SC.B.1.4.2
a.
2
b.
1
c.
4
d.
3
15.
What mass of SrF
2
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
SC.B.1.4.2
a.
9.82 g
b.
9.67 g
c.
10.0 g
d.
10.3 g
16.
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
+H
2
SC.B.1.4.2
a.
2 mol
b.
6 g
c.
3 g
d.
1 mol
17.
The reaction of 5.0 grams of fluorine with excess chlorine produced 5.6 grams of ClF
3
. What percent yield of ClF
3
was obtained?
Cl
2
+ 3F
2
→2ClF
3
SC.B.1.4.2
a.
86%
b.
69%
c.
58%
d.
76%
18.
What is the scientific law that states that matter is not created or destroyed but only transformed in a chemical reaction?
SC.B.1.4.2
a.
law of gravity
b.
law of conservation of energy
c.
law of conservation of momentum
d.
law of conservation of mass
19.
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
2O
SC.B.1.4.2
a.
27%
b.
9%
c.
36%
d.
19%
