Question

What is the work done by 0.5 m^3 saturated ethanol which evaporates to 20 kPa atmosphere to form 2 m^3 of water vapor?

(a) 20 kJ

(b) -20 kJ

(c) 30 kJ

(d) -30 kJ

Answer 1

Right option is (d) -30 kJ

Easy explanation: Work done = -p∆V = -20*(2 – 0.5) = -30 kJ.