Question

Statement I: A reaction with a positive enthalpy and a negative entropy will be spontaneous
BECAUSE
Statement II: The Gibbs free energy for a spontaneous reaction is negative

• A. Statement $1$ and Statement $2$ are correct and Statement 2 is the correct explanation of Statement $1$
• B. Both the Statement $1$ and Statement $2$ are correct and Statement $2$ is NOT the correct explanation of Statement $1$
• C. Statement $1$ is correct but Statement $2$ is not correct
• D. Statement $1$ is not correct but Statement $2$ is correct
• E. Both the Statement $1$ and Statement $2$ are not correct

Answer 1

Answer: (D)

Statement $1$ is not correct but Statement $2$ is correct

We know the formula $\Delta G$$=$$\Delta H$$-$$T$$\Delta S$

Positive enthalpy means $\Delta H$ is $+ve$.

The second term on the right hand side of the equation is already $-ve$. If we take a negative entropy again, the second term on the right hand side will become positive. Hence the total value of $\Delta G$ will be positive. But Gibb's free energy for a spontaneous reaction can't be positive. Hence statement 1 is not correct.

Statement 2 is correct. Gibb's free energy for a spontaneous reaction is negative.

Option D is the correct answer.