Carnot engine: What is the maximum theoretical efficiency possible for a heat engine operating between a reservoir in which ice and water coexist, and a reservoir in which water and steam coexist? The pressure is constant at 1.0 atmosphere for both reservoirs.
A) 27%
B) 45%
C) 73%
D) 17%

Question

Quizplus · Accepted Answer

The maximum theoretical efficiency of a Carnot engine is given by 1 - (Tc/Th), where Tc is the temperature of the cold reservoir and Th is the temperature of the hot reservoir. In this case, the cold reservoir is at 0°C (273.15K) where ice and water coexist, and the hot reservoir is at 100°C (373.15K) where water and steam coexist. Thus, the efficiency = 1 - (273.15/373.15) = 0.267, or 26.7%, which rounds to approximately 27%.

Carnot Engine: What Is the Maximum Theoretical Efficiency Possible for a Heat