When an ideal gas with constant specific heats is throttled adiabatically, with negligible changes in kinetic and potential energies

A rigid insulated cylinder has two compartments separated by a thin membrane. While one compartment contains one kmol nitrogen at a certain pressure and temperature, the other contains one kmol carbon dioxide at the same pressure and temperature. The membrane is ruptured and the two gases are allowed to mix.

Assume that the gases behave as ideal gases. Calculate the increase in entropy of the contents of the cylinder. Universal gas constant equal to $$8314.3$$ $$J/kmol$$ $$K.$$