Use the combined gas law. It's (P1V1)/T1 = (P2V2)/T2.
P1 = 501 kPa, V1 = 5.2 L, T1 = 298 K*; P2 is your unknown, V2 = 7 L, T2 = 372 K*.
*In problems like this, you must always convert Celsius to Kelvin by adding 273 - or 273.15 if you want to be more specific. I used 273.
you should get 465.8387 kPa.
