Skip to contentSkip to Main Site NavigationSkip to Site Left NavigationSkip to Site Utility NavigationSkip to Site SearchSkip to FooterDownload Adobe Reader
CHEM 141
Home » People » John Oakes » CHEM 141 » Thermodynamics

Thermodynamics Definitions

Internal Energy (E) is the total thermal energy in a system.

Work (W) is the work done ON the system.

Heat (q) is the heat added to a system.

Therefore ΔE = q + W     with  W = -PΔV

Adiabatic:  A process for which no heat is exchanged with the system

Adiabatic:   ΔE = W

At constant pressure,  q = H     H is enthalpy

At constant volume   ΔE = q

Exothermic:  A chemical process which produces heat.  ΔH < 0

Endothermic:  A chemical process which absorbs heat.   ΔH > 0

Def:  A state function is a variable whose change only depends on the beginning and final state.  The state function is independent of path taken.


1. The specific heat of a substance is the heat required to raise one gram of that substance by one degree centigrade.   (units: J/gC)

2. The heat capacity of a system is the heat required to raise that particular system by one degree centigrade.    (units J/C)

Last Updated: 11/17/2014
  • Grossmont
  • Cuyamaca
A Member of the Grossmont-Cuyamaca Community College District