Question
Wed December 05, 2012 By: Divyansh

How does the internal energy of a given mass of gas depends upon Pressure, Volume, Temperature of gas, Process in achieving that state of mass of gas?

Expert Reply
Thu December 06, 2012
Temperature: If the temperature of a system rises, the molecules will travel quicker, therefore have more kinetic energy and so the Internal Energy will increase.

Pressure: If the pressure falls but the temp doesn’t change then there is no change in the internal energy of a system.

Volume: The internal energy of an ideal gas depends only on the temperature of the gas, and is independent of the volume. This is pretty obvious, since if there are no interatomic forces then increasing the volume, which effectively increases the mean separation between molecules, is not going to affect the molecular energies in any way. Hence, the energy of the whole gas is unaffected.

State: For most materials that change from solid to liquid the volume increases and so the potential energy of the molecules increases.
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