(Constant Volume)
(Constant Temp.)
| nRT ln | ( |
|
) |
(No Heat)
Integrate to get W
ΔT = 0
(Constant Pressure)
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.
| Process | Basic Idea | Work (W) | ΔEint | Heat (Q) | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Isochoric (Constant Volume) | W = 0 | 0 | n CV ΔT | Q = ΔEint | |||||||
| Isothermal (Constant Temp.) | ΔEint = 0 |
| 0 | Q = W | |||||||
| Adiabatic (No Heat) | Q = 0 | PVγ = constant Integrate to get W | ΔEint = -W | 0 | |||||||
| Free Expansion | Q = 0; ΔT = 0 | 0 | 0 | 0 | |||||||
| Isobaric (Constant Pressure) | no zeroes! | PΔV = nR ΔT | n CV ΔT | n CP ΔT |