Section 16.1
Energy
Practice Test
1.
One calorie is equal to 4.184J. How much energy in joules is supplied by a breakfast bar containing 170 nutritional calories?
a.
170 J
b.
711 J
c.
1.7 x 10
5
J
d.
7.11 x 10
5
J
Hint
2.
The temperature of a 25.0 g sample of aluminum changed from 25°C to37°C when heated. How much energy was absorbed by the aluminum?
Specific Heats of Common Substances at 298 K (25°C)
Specific heat
Substance J/(g·°C)
Water(l)
(liquid)
4.184
Water(s)
(ice)
2.03
Water(g)
(steam)
2.01
Ethanol(l)
(grain alcohol)
2.44
Aluminum(s)
0.897
Granite(s)
0.803
Iron(s)
0.449
Lead(s)
0.129
Silver(s)
0.235
Gold(s)
0.129
a.
10.8 J
b.
22.4 J
c.
269 J
d.
334 J
Hint
3.
The temperature of a 2.5 kg sample of silver was heated from 25°C to 45°C. How much energy was absorbed by the silver?
Specific Heats of Common Substances at 298 K (25°C)
Specific heat
Substance J/(g·°C)
Water(l)
(liquid)
4.184
Water(s)
(ice)
2.03
Water(g)
(steam)
2.01
Ethanol(l)
(grain alcohol)
2.44
Aluminum(s)
0.897
Granite(s)
0.803
Iron(s)
0.449
Lead(s)
0.129
Silver(s)
0.235
Gold(s)
0.129
a.
12 J
b.
118 J
c.
1.2 x 10
4
J
d.
2.6 x 10
4
J
Hint
4.
A body in motion possesses kinetic energy because of its __________.
a.
position
b.
composition
c.
motion
d.
inertia
Hint
5.
If 5.0 grams of copper cools from 35.0°C to 22.6°C and loses 23.6 joules of heat, what is the specific heat of copper?
a.
0.076 J/(g·°C)
b.
3.8 ´ 102 J/(g·°C)
c.
0.38 J/(g·°C)
d.
0.62 J/(g·°C)
Hint
6.
The specific heat of aluminum is 0.900 J/(g·°C). How many joules of heat are absorbed by 30.0 g of aluminum if it is heated from 20.0°C to 40.0°C?
a.
540 J
b.
270 J
c.
812 J
d.
1.14 x 104 J
Hint
7.
The same amount of heat is added to a 10-g sample of each of the following metals. If each metal is initially at 20.0°C, which metal will reach the highest temperature?
a.
beryllium 1.82 J/(g·°C)
b.
calcium 0.653 J/(g·°C)
c.
copper 0.385 J/(g·°C)
d.
gold 0.129 J/(g·°C)
Hint
8.
What is the final temperature of a mixture of chromium metal and water when 50.0 grams of chromium at 15°C (specific heat = 0.448 J/(g·°C)) is added to 25 mL of water (specific heat = 4.18 J/(g·°C)) at 45°C? The density of water is 1 g/mL.
a.
25°C
b.
30°C
c.
35°C
d.
40°C
Hint
