Two cylinders A and B of equal capacity are connected to each other via a stopcock. A contains a gas at standard temperature and pressure. B is completely evacuated. The entire system is thermally insulated. The stopcock is suddenly opened. Answer the following:

**(a)** What is the final pressure of the gas in A and B?

**(b)** What is the change in internal energy of the gas?

**(c)** What is the change in the temperature of the gas?

**(d)** Do the intermediate states of the system (before settling to the final equilibrium state) lie on its P-V-T surface?