During the compression stroke of a certain gasoline engine, the pressure increases from 2atm to 15atm. If the process is adiabatic and the fuel–air mixture behaves as a diatomic ideal gas,

Question

During the compression stroke of a certain gasoline engine, the pressure increases from 2atm to 15atm. If the process is adiabatic and the fuel–air mixture behaves as a diatomic ideal gas,
 by what factor does the volume change?

oobleck · Accepted Answer

PV is constant if P changes by a factor of 15/2, V must change by a factor of 2/15

Damon · Answer

adiabatic P V^gamma = constant

bobpursley · Answer

The value gamma=1.4 is typical for any diatomic gas. Monatomic inert gases, on the other hand, such as Helium, Neon, and Argon, have gamma approx 1.6 . Carbon dioxide, which is triatomic, has a heat capacity ratio gamma=1.28