Question

A reaction has both $\Delta \,H$ and $\Delta \,S$ - ve The rate of reaction

• A. increases with increase in temperature
• B. increases with decrease in temperature
• C. remains unaffected by change in temperature
• D. cannot be predicted for change in temperature

Answer 1

Answer: (B)

increases with decrease in temperature

Answer 2

$\because \,\Delta\, G = \Delta \,H-T \Delta S=-$ ve Given $\Delta \,S$ =- ve $\Delta \,H$ =- ve $\therefore$ To get $\Delta \,G$ =- ve $\Delta \,S$ must be less then $\Delta\, H$ i.e. $\Delta \,H >\,T \Delta S$ Thus the reaction is exotherms and favours and increases with the decrease in temperature