Q8 / 160 · AP EAMCET 2019 (21 Apr Shift 2) · Chemistry

What is the nature of reaction at $298 K$ , if the entropy change and enthalpy change for a chemical reaction are $7.4 cal$ $K^{- 1}$ and $- 2.5 \times 10^{3} cal$ , respectively.

Solution

As Gibbs free energy tells us about the spontenity of the reaction which is calculated as:

$\begin{matrix} ∆ G & = & ∆ H - T ∆ S \\ ∆ G & = & (- 2.5 \times 10^{3}) - 298 \times 7.4 \\ ∆ G & = & - 4705.2 cal \end{matrix}$

As, Gibbs free energy is negative. So, reaction is spontaneous.

Hence, the correct answer is option: 'B'.