Chapter 24:
Chemical Reactions
Practice Test
1.
When propane, C
3
H
8
, is burned, carbon dioxide and water vapor are produced according to the following reaction: C
3
H
8
+ 5O
2
→ 3CO
2
+ 4H
2
O. How much propane is burned if 160.0 g of O
2
are used and 132.0 g of CO
2
and 72.0 g of H
2
O are produced?
a.
44.0 g
b.
28.0 g
c.
88.0 g
d.
160.0 g
Hint
2.
Lithium reacts with oxygen to form lithium oxide according to the equation: 4Li + O
2
→ 2Li
2
O. If 27.8 g of Li react completely with 32.0 g of O
2
, how many grams of Li
2
O are formed?
a.
4.2 g
b.
32.0 g
c.
27.8 g
d.
59.8 g
Hint
3.
When acetylene gas, C
2
H
2
, is burned, carbon dioxide and water are produced. Find the coefficients that balance the chemical equation for the combustion of acetylene: __C
2
H
2
+ __O
2
→ __ CO
2
+ __ H
2
O.
a.
1, 3, 2, 4
b.
2, 1, 2, 2
c.
2, 5, 4, 2
d.
3, 1, 2, 2
Hint
4.
A chemical reaction produces 0.050 g of a product in 0.18 s. In the presence of a catalyst, the reaction produces 0.050 g of the same product in 0.007 s. How much faster is the rate of reaction in the presence of the enzyme?
a.
90.0 times
b.
17.3 times
c.
25.7 times
d.
35.0 times
Hint
5.
Increasing the temperature usually causes the rate of a chemical reaction to increase. If the rate of a chemical reaction doubles if the temperature increases by 10 °C, by what factor does the rate of reaction increase if the temperature increases by 30 °C?
a.
8 times
b.
4 times
c.
6 times
d.
10 times
Hint
6.
What is the set of coefficients that balance the following equation: __Zn(OH)
2
+ __H
3
PO
4
→ __Zn
3
(PO
4
)
2
+ __H
2
O?
a.
3, 2, 1, 6
b.
2, 2, 1, 10
c.
3, 3, 1, 15
d.
1, 2, 3, 13
Hint
7.
Aluminum hydroxide, Al(OH)
3
, decomposes to form aluminum oxide, Al
2
O
3
, and water according to the reaction: 2Al(OH)
3
→ Al
2
O
3
+ 3H
2
O. If 156.0 g of Al(OH)
3
decompose to from 102.0 g of Al
2
O
3
, how many grams of H
2
O are formed?
a.
54.0 g
b.
104.5 g
c.
51.0 g
d.
78.0 g
Hint
8.
What is the set of coefficients that balance the following equation: __CS
2
+ __O
2
→ __CO
2
+ __SO
2
?
a.
1, 1, 1, 2
b.
1, 3, 1, 2
c.
1, 2, 1, 2
d.
1, 2, 1, 1
Hint
9.
In the following balanced chemical reaction one of the products is represented by the symbol X: BaCO
3
+ C + H
2
O → Ba(OH)
2
+ H
2
O + 2X. What is the formula for the compound represented by X?
a.
CO
b.
COH
c.
H
2
CO
3
d.
CO
2
Hint
10.
When methane, CH
4
, is burned, 50.1 kJ of energy per gram of methane are released. When propane, C
3
H
8
, is burned, 45.8 kJ of energy per gram of propane are released. If a mixture of 1.0 g of methane and 1.0 g of propane is burned, how much energy is released per gram of mixture?
a.
50.1 kJ/g
b.
48.0 kJ/g
c.
95.9 kJ/g
d.
4.3 kJ/g
Hint
