Question

Isothermal Process of the First Law of Thermodynamics.

Answer 1

In an isothermal process heat is transferred from a system to the surroundings with out any change in termperature i.e. ΔT = 0 . 

For an ideal gas δu = 0 for an isothermal process. This is because the internal energy of such a gas is solely made up of the kinetic energy of constituent atoms and molecules and this does not change as long as temperature remains constant. Hence for an ideal gas from the first law of thermodynamics we have

δQ = δW

Now we know that the work done by a gas diving are isothermal expansion is given by

δW = pdv

For an ideal gas expanding from an initial volume v₁ to a final value v₂ , the work done equals