Chemistry please help.

Question

A sample of compressed methane has a volume of 0.648 L at pressure of 503kPa at 75.0C. What pressure would it be compressed to in order to have a volume of 0. 216 L and a temperature of 50.0C?

Answer 1

Initial volume = V1 = 0.648 L

Initial pressure = P1 = 503 kPa

Initial temperature = T1 = 75.0ºC + 273 = 348K (temperature must be in Kelvin)

Final volume = V2 = 0.216 L

Final pressure = P2 = ?

Final temperature = 50.0ºC + 273 = 323K

Use the Combined Gas Law: P1V1/T1 = P2V2/T2 and solve for P2:

(503 kPa)(0.648 L) / 348K = (P2)(0.216 L) / 323K

P2 = 1401 kPa