What is the final pressure of the gas? What is the final temperature of the gas?

Question

A container of gas at 2.00 atm pressure and 117 degrees Celsius is compressed at constant temperature until the volume is halved. It is then further compressed at constant pressure until the volume is halved again.

What is the final pressure of the gas?

What is the final temperature of the gas?

PV= nRT

(2.00)V= n (8.314)(390.15 K)

where do i go from here?

Answer 1

1.  if T = constant ==>  p1 .V1= p2 . V2  

       p1 = 2 atm and V2 = V1 / 2  ==>  p2 = 4 atm!!

2.  if p = constant ==>  V1 / T1 = V2 / T2

      T1 = 390 K  , V2 = V1 / 2   ==> T2 = 195 K

  

so final :

final pressure = 4atm

final temperature = 195 K