Question

Two moles of helium are initially at a temperature of 30.0?C and occupy a volume of 3.20

Answer 1

There are two steps first is the expansion at conatant pressure and the next is adiabatic expansion.

Let the volume change at constant pressure be from V to 2V(V=3.2 x 10^-2 m³ ).Since pressure is constant the temperature changes to 2T(T is the initial temp. Calculate it using PV=nRT for initial conditions).Now thw work done would be P(2V-V)=PV.Calculate dU and get Q.

Now for adiabatic expansion the temperature changes from 2T to T and Q will be 0.Get dU=dW..Now calculate the rest stuff.If there are any doubts then comment.