Will there be a temp change in free expansion
In a real gas, the internal energy is the sum of the kinetic energy of the molecules and their potential energy of interaction. An ideal gas is the limit of real gas behavior in the limit of large molar volumes in which the potential energy of interaction of the molecules approaches zero. The kinetic energy of the molecules depends only on temperature, but the potential energy of interaction of the molecules depends on both temperature and specific volume. The temperature of an ideal gas does not change when subjected to free expansion, but it does change for a real gas.  So the deviation from ideal gas behavior caused by potential energy of interaction of the molecules is what causes the temperature of a real gas to change in free expansion.