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Isoctherm

Definition

... a process at constant temperature, denoted by a reciprocal function on a pV diagram and a horizontal line on a Ts diagram.

Where it occurs.

In the theoretical Carnot and Sterling Cycles, heat is added and rejected at constant temperature.

Special features

For an ideal gas, heat addition and work output are equal.

How to draw it

Locate the POI and press the isotherm button.

The theory

For an ideal gas at constant temperature pressure and volume are in inverse proportion to each other. Or, from the Ideal Gas Law, $$ p = mRT \times \frac{1}{V} $$ The calculations of ideal gas internal energy, enthalpy and entropy are explained in conjunction with the point of interest.

Exercises

Click on the graph to get a POI and plot an isotherm through it. Click along the isotherm to set new POIs and note how - within the constraints of setting POIs by eye - temperature and internal energy are constant.

Links

... to follow.