Question

Three samples A, B, and C of the same gas initially having the same volume and pressure are expanded to double their initial volume. One sample A is expanded isothermally, B has expanded adiabatically and C is expanded isobarically. In which case is the work done minimum?

Answer 1

Adiabatic expansion:

1. An expansion in which the system has no thermal contact with its surroundings and works at the expenditure of its internal energy is called adiabatic expansion.
2. When compared to an isothermal expansion, which now has both heat flow but also work done, an adiabatic expansion has much less work done and no convective heat, resulting in decreased internal energy.

Therefore, the minimum work is done in the case of adiabatic expansion.