Section 12.1
What is stoichiometry?
Practice Test
1.
What is the scientific law that states that matter is not created or destroyed but only transformed in a chemical reaction?
a.
law of conservation of energy
b.
law of conservation of mass
c.
law of conservation of momentum
d.
law of gravity
Hint
2.
What is the first thing you must do to solve a stoichiometric problem?
a.
Find the limiting reactant.
b.
Find the excess reactant.
c.
Write a balanced chemical equation.
d.
Find the empirical formula.
Hint
3.
What do the coefficients in the following balanced chemical equation mean?
2H
2
+ O
2
→ 2H
2
O
a.
2 moles of hydrogen and 1 mole of oxygen in the reactants
b.
2 moles of oxygen and 1 mole of hydrogen in the reactants
c.
2 moles of oxygen and 1 mole of hydrogen in the products
d.
2 moles of hydrogen and 1 mole of oxygen in the products
Hint
4.
What is the ratio between the coefficients of any two substances in a balanced equation?
a.
molar mass balanced equation
b.
mole ratio
c.
quadratic equation
d.
chemical formula
Hint
5.
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.
HCl + CaCl
2
→ CaCO
3
+ CO
2
+ H
2
O
b.
HCl + CaCO
3
→ CaCl
2
+ CO
2
+ H
2
O
c.
2HCl + CaCO
3
→ CaCl
2
+ CO
2
+ H
2
O
d.
2HCl + CaCl
2
→ CaCO
3
+ CO
2
+ 2H
2
O
Hint
6.
How many moles of CO
2
would be produced from 56 moles of O
2
according to the following balanced equation?
2C
2
H
6
+ 7O
2
→ 4CO
2
+ 6H
2
O
a.
16 mol
b.
32 mol
c.
224 mol
d.
48 mol
Hint
7.
How many grams of Fe
2
O
3
are present in 0.82 mol Fe
2
O
3
?
a.
130 g
b.
65 g
c.
195 g
d.
260 g
Hint
8.
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.
16 g
b.
32 g
c.
64 g
d.
80 g
Hint
9.
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
a.
2
b.
3
c.
4
d.
1
Hint
10.
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.
1.0 mol
b.
1.5 mol
c.
2.0 mol
d.
4.0 mol
Hint
11.
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
a.
5
b.
10
c.
15
d.
20
Hint
