Question

Molar heat capacity of diamond carbon in equilibrium with graphite carbon at constant pressure is :

• A. zero
• B. Infinity
• C. 3.4 kJ/mol
• D. -3.4 kJ/mol

Answer 1

The correct option is B Infinity

Molar heat capacity of diamond carbon in equilibrium with graphite carbon at constant pressure is infinity.
The relationship between the molar heat capacity and the temperature is as shown below.

$C_p={\left[\frac{\Delta H}{\Delta T}\right]}_p$.

At equilibrium during phase transition $\Delta T=0$

Hence, the molar heat capacity will be infinite.