3. An isolated cylinder is divided by a partition into two compartments. Compartment A contains 0.2 mol of pure methane at 50C, 1 bar. Compartment B contains 0.8 mol of an equimolar methane-ethane mixture at 100C, 1 bar. If the partition is removed and the gases mix adiabatically and completely. 3.1 What is the composition of the final mixture? (1 point) 3.2 What is the temperature and pressure at the end of the process? (2 points) 3.3 What is the entropy change? (3 points) Additional data: The ideal-gas Co's of the pure components are : ethane: 10.3 R; methane: 6.2 R; where R is the ideal gas constant