In a steam engine, steam in a cylinder expands against a piston exerting 10.00 atm of external pressure.The volume of the cylinder increases by 10.00 L and simultaneously the steam cools, losing 3.000 * 10³ 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 difference between the work done by the steam and 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:$$W = P\Delta V = (10.00 	ext{ atm})(10.00 	ext{ L}) = 101.3 	ext{ kJ}$$The heat lost by the steam is given as 3.000 kJ. Therefore, the change in energy of the steam is:$$\Delta E = W - Q = 101.3 	ext{ kJ} - 3.000 	ext{ kJ} = 98.3 	ext{ kJ}$$The correct answer is A.

In a Steam Engine, Steam in a Cylinder Expands Against