Question

4.0 L of an ideal gas is allowed to expand isothermally into vacuum until the total volume is 20 L. The amount of heat absorbed in this expansion is ____ L atm.

Answer 1

Work done $= –P_{ext} Δv$
∵ $P_{ext}= 0$ (vacuum)
∴ $w = 0, ΔU = 0$ (as the process is isothermal)
So, $q = 0$