Use the following information to answer questions 16–18.
A substance is a solid at 15°C. A student
heated a sample of the solid substance and
recorded the temperature at one-minute
intervals in the data table below.
0
1
2.
3
4
5
6
Time (min)
Temp (°C)
15
32
46
53
53
53
53
7
8
9
10
11
12
13
Time (min)
Temp (°C)
53
53
53
53
60
65
70
16. Based on the data table, what is the
melting point of this substance?
17. What is the evidence that the average
kinetic energy of the particles of this
substance is increasing during the first
three minutes?
18. The heat of fusion for this substance is
122 joules per gram. How many joules
of heat are needed to melt 7.50 grams of
this substance at its melting point?