Principle

Heat is added to a gas in a glass vessel by an electric heater which is switched on briefly. The temperature increase results in a pressure increase, which is measured with a manometer. Under isobaric conditions a temperature increase results in a volume dilatation, which can be read from a gas syringe. The molar heat capacities Cv and Cp are calculated from the pressure or volume change.

Benefits


Determination of cp and cv

For both demonstration and student experiments

Suitable for many different gases



Tasks

Determine the molar heat capacities of air at constant volume Cv and at constant pressure Cp.

What you can learn about


Equation of state for ideal gases

First law of thermodynamics

Universal gas constant

Degree of freedom

Mole volumes

Isobars

Isotherms

Isochors and adiabatic changes of state