The initial pressure, temperature & volume of 1 mol of a gas are `P_(1),T_(1) and V_(1)` respectively. The state of the gas is changed by the following two ways. Will the internal energy change be the same in both cases?
(1) `P_(1)V_(1)T_(2) underset("Process")overset("Reversible")toP_(2)V_(2)T_(2)`
(2) `P_(1)V_(1)T_(1) underset("process")overset("Irreversible")toP_(2)V_(2)T_(2)`.

Explanation

The internal energy of a system is a state function. The change in internal energy in a process depends only on the initial and final states of the system. It does ot depend on the path used to arrive at the state. Since the initial and final state are the same in (1) and (2), the internal energy change will also be the same.