(i) Equal masses of four different substances are heated such that the rate of heat supply is same. The rise in temperature with respect to time is plotted on a graph. Which of the following substances has the highest specific heat capacity ?

1. A
2. B
3. C
4. D

(ii) Would you use this material for making a calorimeter? Give reason for your answer.

(i) D

(ii) No

Reason —

(i) When equal masses of substances are heated at the same rate, the rise in temperature depends on the specific heat capacity using

Q = mcΔT

where

• m is mass,
• c is specific heat capacity, and
• Δt is the change in temperature.

For the same heat supplied and mass, a substance with higher specific heat capacity shows a smaller rise in temperature, i.e., a less steep slope on the graph.

Since curve D has the least slope, it corresponds to the highest specific heat capacity.

Hence, substance D has the highest specific heat capacity.

(ii) A calorimeter should be made of a material having low specific heat capacity, so that it absorbs very little heat itself.
But this substance has the highest specific heat capacity, so it will absorb more heat, which is not suitable for a calorimeter.
Therefore, this material is not suitable for making a calorimeter.