Two substances have the same mass and are both initially at 200°C. They both absorb 150 J of energy. Which substance will have the higher temperature, the one with the higher or the lower specific heat?

1 Answer
Jan 3, 2016

Answer:

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.