Which one of the following is an intensive property of a thermodynamic system?

The molar specific heat at constant volume of an ideal gas is equal to $$2.5$$ times the universal gas constant ($$8.314$$ $$J/mol.K$$). When the temperature increases by $$100$$ $$K$$, the change in molar specific enthalpy is _______________ $$J/mol.$$

The internal energy of an ideal gas is a function of

The Vander-waals equation of state is $$\left( {p + {a \over {{v^2}}}} \right)\left( {v - b} \right) = RT,$$ where $$p$$ is pressure, $$v$$ is specific volume, $$T$$ is temperature and $$R$$ is characteristic gas constant. The $$S{\rm I}$$ unit of a is