Equal amounts of heat are added to equal masses of substances A and B at the same temperature, but substance B gets hotter. What is true of their heat capacities (c) ?

The one with the lower specific heat.

Explanation:

A substance's specific heat tells you how much heat must be added to / removed from a

1-g

sample of this substance in order to get its temperature to change by

1

∘

C

.

When energy in the form of heat is absorbed, a substance's specific heat tells you exactl; y how much heat is needed in order to increase the temperature of

1 g

of this substance by

1

∘

C

.

This means that the higher the specific heat of a substance, the more heat will be needed in order to get the temperature of

1 g

to increase by

1

∘

C

.

In your case, two substances, let's say

A

and

B

, start at the temperature,

200

∘

C

and they both absorb

150 J

of heat. Moreover, they both have the same mass.

If the specific heat of

A

is higher than the specific heat of

B

, you can say that it will take more energy to raise the temperature of

A

by

1

∘

C

than to raise the temperature of

B

by

1

∘

C

.

So, if

B

absorbs

150 J

and gets to a final temperature

T

B

, the fact that

A

has a higher specific heat will tell you that absorbing

150 J

of heat will not get the final temperature of

A

,

T

A

, to the same value as

T

B

.

You can thus say that

T

A

<

T

B

The substance with the lower specific heat will heat up more than the substance with the higher specific heat.