Adiabatic compressions

Definition

Adiabatic compression is a process in which a gas is compressed without any heat exchange with its surroundings. The internal energy of the gas increases, resulting in an increase in temperature.

5 Must Know Facts For Your Next Test

1. During adiabatic compression, the work done on the gas increases its internal energy.
2. No heat is transferred into or out of the system during adiabatic processes ($Q = 0$).
3. For an ideal gas, adiabatic compression follows Poisson's equation: $PV^{\gamma} = \text{constant}$, where $\gamma$ is the adiabatic index.
4. $\gamma$ (the adiabatic index) is the ratio of specific heats at constant pressure and volume ($C_p/C_v$).
5. The temperature of the gas rises during adiabatic compression because all the work done on it converts into internal energy.

Review Questions

• What happens to the temperature of a gas during adiabatic compression?
• Why does no heat transfer occur during an adiabatic process?
• What equation describes the relationship between pressure and volume for an ideal gas undergoing adiabatic compression?

Related terms

Isothermal Process: A thermodynamic process in which the temperature remains constant while heat can be exchanged with surroundings.

$\gamma$ (Adiabatic Index): The ratio of specific heats at constant pressure ($C_p$) and constant volume ($C_v$), typically greater than one for gases.

$PV^{\gamma} = \text{constant}$: Poisson's equation describing the relationship between pressure and volume during an adiabatic process for an ideal gas.