Chemistry - Thermodynamics - I Question with Solution | TestHub

(A) Reversible isothermal compression

In a reversible process, the system changes very slowly and remains in equilibrium.

For isothermal compression of an ideal gas, work done depends on the path.

A reversible path gives minimum magnitude of work done by surroundings on system (i.e., most “efficient” compression).

So (A) is correct.

(B) Cyclic process and work

In a cyclic process, initial and final states are the same, so:

$\Delta U=0$ always

But work depends on the path taken.

In irreversible cycles, the path is not retraceable, so the net work over the cycle is generally not zero.

So (B) is correct.

(C) Adiabatic relation

Correct adiabatic relations are:

$P{V}^{\gamma }=constant$

$T{V}^{\gamma -1}=constant$

The given expression $T^{(C_{p,m}/R)}\cdot P=constant$ is not a valid thermodynamic relation.

So (C) is incorrect.

(D) Entropy in reversible adiabatic process

An adiabatic process means $q=0$.

If it is also reversible, then no entropy is produced:

$\Delta S=0$

So (D) is correct.