What is the final pressure of an adiabatically compressed gas in a container?

[de3tz]

Homework Statement

a container with air (M = 29 g/mol, treated as an ideal gas). In the container, we have 2.0 L of the gas with p1 = 1.0 atm at T1 = – 50C. The gas is compressed adiabatically to a final volume of 0.5 L. What is its final pressure?

Homework Equations

I am really not sure, as the moles are not given, and the only equation I have encountered for this problem involves moles.

The Attempt at a Solution

I attempted using ideal gas law, but since the process is adiabatic, the answer does not apply. I am truly confused.

 

[dacruick]

Do you think you could find moles? I mean, you have Pressure, Volume, and Temperature.