IIT-JEE 2008 · Paper 1 · Chemistry Q60

ChemistryAssertion and reason+3 / -1Question 60 of 69

STATEMENT-1: For every chemical reaction at equilibrium, standard Gibbs energy of reaction is zero.

and

STATEMENT-2: At constant temperature and pressure, chemical reactions are spontaneous in the direction of decreasing Gibbs energy.

STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is a correct explanation for STATEMENT-1

STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is NOT a correct explanation for STATEMENT-1

STATEMENT-1 is True, STATEMENT-2 is False

STATEMENT-1 is False, STATEMENT-2 is True

Answer and worked solution

Official answer: D

Statement 1. At equilibrium $\Delta_rG=0$ , but $\Delta_rG^\circ=-RT\ln K$ , which is zero only when $K=1$ . False.

Statement 2. At constant $T$ and $P$ , spontaneous change lowers $G$ . True.

(D)

IIT-JEE 2008 · Paper 1, Chemistry question 60