On a day when atmospheric pressure if 76cmHg, the pressure gauge on the tank reads the pressure inside to be 400cmHg. the gas in the tank has a temperature of 9 degrees celcuis. If the tank is heated to 31 degrees celcuis by the sun, and no gas exists, what will the pressure gauge read?

Answer 1

P V = n R T
P/T = n R/V = constant here
T1 = 273 + 9
T2 = 273 + 31

P1 = 76 + 400
P2 = 76 + x where x is new gage pressure

P2/T2 = P1/T1
so P2 = (T2/T1) P1
x = P2 - 76