For the reaction at 298 K, 2A+B $\to C$

$△$ H = 400 KJ $m o l^{- 1}$ and $△$ S = 0.02 KJ $K^{- 1}$ $m o l^{- 1}$
At what temperature will the reaction become spontaneous considering $△$ H and $△$ S to be constant over the temperature range?

Open in App

Solution

$Δ G = Δ H - T Δ S$

Assuming that equation at equilibrium then

$Δ G$ = $0$

$Δ G = Δ H - T Δ S = 0$

$T = \frac{Δ H}{Δ S} = \frac{400}{0.2} = 2000 K$ .

For the reaction to be spontaneous $Δ G$ must be negative.
Therefore temprature should be greater than 2000 K.

Suggest Corrections

Similar questions

For the reaction at 298 K,

2A + B → C

ΔH = 400 kJ mol^–1 and ΔS = 0.2 kJ K^–1 mol^–1

At what temperature will the reaction become spontaneous considering ΔH and ΔS to be constant over the temperature range?

2 A + B \to C

298 K

Δ H = 400 {kJ mol}^{- 1}

Δ S = 0.2 {kJ K}^{- 1} {mol}^{- 1}

Δ H

Δ S

M_{2} O (s) \to 2 M (s) + \frac{1}{2} O_{2} (g); Δ H = 30 k J m o l^{- 1} a n d Δ S = 0.07 k J K^{- 1} m o l^{- 1} a t 1 a t m .

K

△ H = + 29 k J m o l^{- 1}; △ S = - 35 J K^{- 1} m o l^{- 1}

Join BYJU'S Learning Program