Question

An ideal gas expands isothermally, performing 3.40x103 J of work in the process.

Calculate (a) the change in the internal energy of the gas, and (b) the heat

absorbed during the expansion.

Answer 1

(a) Since the temperature is constant and the change in internal energy depends on the change in temperature, $\Delta U=0.$

(b) According to the first law of thermodynamics, $Q=\Delta U+W=0+3.4·10^3=3.4·10^3\text{ J}.$