Question

Assertion :Statement-I : Decrease of free energy during the process under constant temperature and pressure
provides a measure of its spontaneity.
Because Reason: Statement-II : A spontaneous change must have +ve sign of $\Delta S_{system}$.

• A. Statement-I is true, Statement-II is true ; Statement-II is correct explanation for Statement-I.
• B. Statement-I is true, Statement-II is true ; Statement-II is not a correct explanation for Statement-I.
• C. Statement-I is true, Statement-II is false.
• D. Statement-I is false, Statement-II is true.

Answer 1

The correct option is C Statement-I is true, Statement-II is false.

Free Energy change is a combination of enthalpy change, entropy change, and temperature that can be used to determine whether a process is spontaneous or nonspontaneous. It is used to predict reaction's spontaneity of a reaction with constant temperature and pressure, when ΔG is negative, the reaction is possibly spontaneous. When ΔG is positive, the reaction is possibly not spontaneous. When ΔG is zero, there is no equilibrium and therefore, there is no reaction.

ΔH ΔS spontaneous

Negative Positive Yes

Negative Negative possibly (at low temperature)

Positive Positive possibly (at high temperature)

Positive Negative No