Question

Write the mathematical equation for the first law of thermodynamics for an isothermal process.

Deduce the first law of thermodynamics for the isothermal process.

Answer 1

For a given temperature (T) and internal energy (U) of the remains constant.

∴ ΔT = 0

∴ ΔU = 0

First law of thermodynamic

ΔU = Q + W

0 = Q + W  ...(∵ ΔU = 0)

∴ Q = – W