Hellox is helium-oxygen mixture that may be used in scuba tanks for divers working at great depths. It is also used medically as a breathing treatment.
A 6.25-L tank holds helium gas at a pressure of 1031 psi. A second 6.25-L tank holds oxygen at a pressure of 274.1 psi. The two gases are mixed in a 6.25-L tank. If the temperature remains the same throughout the process, what is the pressure of the gas mixture in the tank? Assume ideal gas behaviour.