Molar heat capacity for a gas
Have a unique value
can have different value
depends on the process
both 2 and 3
For a gas, the molar heat capacity C is the heat required to increase the temperature of 1 mole of gas by 1 K.
The heat capacity depends on whether the heat is added at constant volume or constant pressure.
Molar heat capacity of gas can have different values depending upon the process followed.