Thermodynamic Processes

Thermodynamics is all about energy.

Internal energy is a measure of the total kinetic energy of the atoms and molecules. It is directly proportional to temperature.

First Law: ΔEint = Q - W

Ideal gas law: PV = nRT or PV = NkT

Work is the area under the P-V curve. It depends on the process.

The change in internal energy ΔEint is independent of the process, depending only on the change in temperature.

CV depends on whether the gas is monatomic, diatomic, etc.

The heat also depends on the process.

A Summary of Thermodynamic Processes

ProcessBasic IdeaWork (W)ΔEint Heat (Q)
Isochoric
(Constant Volume)
W = 0 0 n CV ΔT Q = ΔEint
Isothermal
(Constant Temp.)
ΔEint = 0
nRT ln (
Vf
Vi
)
0 Q = W
Adiabatic
(No Heat)
Q = 0PVγ = constant
Integrate to get W
ΔEint = -W0
Free ExpansionQ = 0;
ΔT = 0
000
Isobaric
(Constant Pressure)
no zeroes!PΔV = nR ΔT n CV ΔT n CP ΔT