Question

For a spontaneous process at constant pressure and temperature, \(\Delta G^\circ\) and \(\Delta S\) are:

• A. ∆G° = 0, ∆S = 0
• B. ∆G° < 0, ∆S > 0
• C. ∆G° > 0, ∆S > 0
• D. ∆G° = 1, ∆S = 1

Hint:

Always remember: Spontaneous process $\Rightarrow \Delta G < 0$. At equilibrium, \(\Delta G = 0\).

Answer 1

The Correct Option is B

Concept: The spontaneity of a process at constant temperature and pressure is determined by Gibbs free energy. The Gibbs free energy equation is: \[ \Delta G = \Delta H - T\Delta S \] A process is spontaneous if: \[ \Delta G < 0 \] The entropy change indicates the degree of disorder in a system. A positive entropy change generally favors spontaneity.

Step 1: Recall the criterion for spontaneity. For a spontaneous process: \[ \boxed{\Delta G < 0} \] This is the fundamental condition.

Step 2: Consider the entropy change. Spontaneous processes generally proceed toward greater randomness. Hence entropy tends to increase. \[ \boxed{\Delta S > 0} \]

Step 3: Choose the correct option. Combining both conditions: \[ \Delta G^\circ < 0 \] and \[ \Delta S > 0 \] Therefore, \[ \boxed{(2)} \] is the correct answer.