A Mollier diagram is another name for which thermodynamic diagram?

• A. Temperature-Entropy diagram
• B. Enthalpy-Pressure diagram
• C. Enthalpy-Entropy diagram
• D. Pressure-Volume diagram

Answer: (C)

The Mollier diagram is an enthalpy-entropy diagram. It pairs enthalpy (h) on one axis with entropy (s) on the other, and it often includes curves of constant pressure as well as lines representing saturated and moist-state regions. This format is especially useful for analyzing steam and refrigeration cycles because it directly tracks energy content (enthalpy) alongside disorder or irreversibility (entropy) as the working fluid moves through components like turbines, boilers, condensers, and throttling devices. In contrast, a temperature-entropy diagram, an enthalpy-pressure diagram, or a pressure-volume diagram use different primary variables, so they don’t carry the same typical interpretive framework as the Mollier chart.