In a steam engine, steam in a cylinder expands against a piston, exerting 10 atm of external pressure. The volume of the cylinder increases by 10 L and simultaneously the steam cools, losing 3,000 kJ of energy to the surroundings. What is the change in energy of the steam? (101.3 J = 1 L atm)

Question

Quizplus · Accepted Answer

The change in energy of the steam is the work done by the steam minus the heat lost by the steam. The work done by the steam is given by the product of the external pressure and the change in volume. The heat lost by the steam is given by the amount of energy lost to the surroundings. Therefore, the change in energy of the steam is:Change in energy = Work done - Heat lostChange in energy = (10 atm)(10 L)(101.3 J/L atm) - 3,000 kJChange in energy = 10,130 J - 3,000 kJChange in energy = -2,990 kJTherefore, the correct answer is A.

In a Steam Engine, Steam in a Cylinder Expands Against