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

The specific heats of an ideal gas depend on its

The definition of 1 K as per the internationally accepted temperature scale is