Question

A cylinder containing some gas A is fitted with an idealized piston. Gas A is at 1.2 atm, 10.0 L and at 432K. What external pressure is required to compress this gas irreversibly to a final volume of 3.20L?
0.12 atm
0.33 atm
0.45 atm
0.52 atm

Answer 1

The external pressure is balanced by the pressure exerted by the gas on the piston.
Using the Boyle’s Law
P_1 V_1=P_2 V_2
P_2=P_extr=(P_1 V_1)/V_2
P_2=P_extr=(1.2 atm×10.0 L)/(3.20 L)=3.75 atm