LearnChemE

Energy Balances with Phase Changes: Screencasts

Overview of sensible and latent heats and how to account for phase changes in energy balances.

We suggest that after watching this screencast, you list the important points as a way to increase retention.

Provides an overview of latent heat. Calculates the heat required to vaporize and condense 100 mol of water at 100°C and atmospheric pressure.

We suggest that after watching this screencast, you list the important points as a way to increase retention.

Important Equations:

Overview of sensible and latent heats and how to account for phase changes in energy balances.

\[\Delta H_m = \Delta U_m\]

where \(\Delta H_m\) is the enthalpy change when a solid melts, and \(\Delta U_m\) is the internal energy change when a solid melts.

Sensible Heat:   

\[\Delta H = \int C_P dT\]

where \(\Delta H\) is the enthalpy change, \(C_P\) is the heat capacity, and \(T\) is temperature.

Latent Heat for vaporization:

\[\Delta H = \Delta H_{vaporization}\]

\[\Delta H_{condensation} = – \Delta H_{vaporization}\]