Rigid tank contains a mixture of 1 lbm of methane gas and 5 lbm of O2 at

Question:

Rigid tank contains a mixture of 1 lbm of methane gas and 5 lbm of O2 at 77oF and 25 psia. Upon ignition, the contents of the tank burns completely. If the final temperature is 1500oR, determine
(a) The final pressure in the tank and
(b) The amount of heat transfer during the process.