Answer
a. $\Delta U = 0$
b. $4.30\times10^3J $
Work Step by Step
Use the first law of thermodynamics and the definition of internal energy. Work is done by the gas, so W is positive.
a. The temperature does not change. $\Delta U = 0$.
b. $\Delta U=Q-W$ so $Q=\Delta U+W=0+4.30\times10^3J=4.30\times10^3J $.