WorksheetsThermochemistry
Total questions: 21
Worksheet time: 1hrs 2mins
Name
Class
Date
1.
The unit(s) for heat are?
a)
calories
b)
joules
c)
calories or joules
2.
135 g of aluminum (initially at 400oC) are mixed with an unknown mass of water (initially at 25oC). When thermal equilibrium is reached, the system has a temperature of 80oC. Find the mass of the water.
a)
197.2g
b)
168.6g
c)
168.6J
d)
23.1g
3.
A piece of metal with a mass of 32.8 g is heated to 100.5°C and dropped into 138.2 g of water at 20.0°C. The final temperature of the system is 30.2°C. What is the specific heat capacity of the metal?
a)
2.56 J/g°C
b)
0.391 J/g°C
c)
5.29 J/g°C
d)
3.50 J/g°C
4.
In the lab, an experimenter mixes 75.0 g of water (initially at 30oC) with 83.8 g of a solid metal (initially at 600oC). At thermal equilibrium, he measures a final temperature of 50.0oC. What was the specific heat of the metal?
a)
0.672 J/g ⁰C
b)
0.533 ⁰C
c)
1.156 J/g ⁰C
d)
0.133 J/g ⁰C
5.
The specific heat of a substance is the amount of energy needed to raise the temperature of one gram, one degree Celsius of a substance.
a)
True
b)
False
c)
sometimes
6.
As a reaction is taking place, the student notices that the temperature has dropped. This indicates that the system has increased in energy. What type of process is this?
a)
Endothermic
b)
Exothermic
7.
For the formula:
Q= m c ∆T
The units for specific heat are:
Q= m c ∆T
The units for specific heat are:
a)
g /J C
b)
J/g⁰C
c)
kJ/g
d)
KJ/⁰Cg
8.
Using the heat equation, what would the formula look like if we were solving for change in temperature?
a)
ΔT c =Qm
b)
ΔT=Q/mc
c)
ΔT = Qm/c
d)
mcQ=∆T
9.
A sample of iron receives 50 J of heat energy that raises the temperature of the iron 25.0°C. If iron has a specific heat of .10 J/g°C, what is the mass of the iron sample?
a)
25g
b)
20g
c)
17g
d)
50g
10.
What would be the effect on particles if more heat is supplied to the system?
a)
They would slow down
b)
They would stop moving
c)
They would speed up
d)
There would be no effect
11.
In an exothermic process, the surroundings are are gaining energy.
a)
True
b)
False
12.
If 238 J of heat is absorbed by a sample of metal with a mass of 40.7 g, and it raises the temperature from 20.0°C to 32.4°C, what is the specific heat capacity of the metal? (show your work)
a)
2.34 J/g°C
b)
0.472 J/g°C
c)
6.13 J/g°C
d)
0.163 J/g°C
13.
In an exothermic process, the surroundings are are gaining energy.
a)
True
b)
False
14.
Heat flows from ___ to ___ temperatures.
a)
neither
b)
cold, hot
c)
both
d)
hot, cold
15.
A 97 g sample of gold at 785oC is dropped into 323 g of water, which has an initial temperature of 15oC. If gold has a specific heat of 0.129 J/g.oC, what is the final temperature of the mixture? Assume that the gold experiences no change in its state of matter.
a)
226.1⁰C
b)
122.1⁰C
c)
25.1⁰C
d)
22.1oC
16.
If 24 g of sodium chloride (specific heat 0.864 J/g⁰C) at 25oC are mixed with 272 g of mercury (specific heat 0.125 J/g⁰C) at 50oC, find the final temperature.
a)
59.2oC
b)
49.1oC
c)
41.1⁰C
d)
6.02oC
17.
When ice melts (in the phase change), the temperature?
a)
increases
b)
decreases
c)
remains the same
d)
depends on the situation
18.
Which has more heat (energy), a cup of water at 100 °C, a 5 liter pot of water at 100 °C, or a bathtub of water at 100 °C?
a)
cup
b)
5 quart pot
c)
bathtub
d)
all equal
19.
A piece of metal with a mass of 32.8 g is heated to 100.5°C and dropped into 138.2 g of water at 20.0°C. The final temperature of the system is 30.2°C. What is the specific heat capacity of the metal? (show your work)
a)
2.56 J/g°C
b)
0.391 J/g°C
c)
5.29 J/g°C
d)
3.50 J/g°C
20.
A 322 g sample of lead (specific heat = 0.138 J/goC) is placed into 264 g of water at 25oC. If the system’s final temperature is 46oC, what was the initial temperature of the lead?
a)
543⁰C
b)
658⁰C
c)
-568⁰C
d)
568⁰C
21.
I place a cube of steel 100 cm³ in a room and place a 100 cm³ cube of oak next to it. The room they are in is 37⁰C. They sit there for 1 day. If I measure their temperature the next day with a probe, what will their respective temperatures be? (assume that what they are sitting on is not affecting their temperature)
a)
They are unchanged from the original Temperature
b)
Steel 26⁰C Oak 37⁰C
c)
Steel 37⁰C Oak 37⁰C
d)
Steel 47⁰C Oak 57⁰C
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