We treat dry air as an ideal gas.
Volume = V1 T1 = 300 Kelvin Pressure = P1
V2 = V1 / 9 γ = ratio of specific heats = 1.5 T2 = ? P2 = ?
number of moles n is fixed.
P1 V1 / T1 = P2 V2 / T2
P1 V1 / 300 = P2 (V1 /9) / T2 => T2 = 33.33 P2 / P1
Is the gas compressed adiabatically and/or suddenly ? with no energy exchanged between the system and the environment ? It has to be mentioned whether it was an isobaric compression or adiabatic compression.
Otherwise the final pressure is to be mentioned. T2 = 300 * √9 = 900⁰K = 627⁰ C