a
Given chemical reaction:

\({A} \underset{{T}\, 300\, {~K}}{\longrightarrow} {B}\)

\([\Delta {G}]_{{P}, {T}}=-49.4\, {~kJ} / {mol}\)

\(\Delta {H}_{{rxn}}=51.4 \,{~kJ} / {mol}\)

\(\Delta {S}_{{rxn}}=?\)

\(\Rightarrow\) From the relation \([\Delta {G}]_{{P}, {T}}=\Delta {H}-{T} \Delta {S}\)

\(\Rightarrow \Delta S_{\text {rxn }} =\frac{\Delta H_{r x n}-[\Delta G]_{p, T}}{T}\)

\(=\frac{[51.4-(-49.4)] \times 100}{300} \,\frac{{J}}{{mol} {K}}\)

\(\Rightarrow \Delta {S}_{{rxn}} =336\, \frac{{J}}{{mol} {K}}\)