Question # For the reaction at ( 298 mathrm{K}, 2 mathrm{A}+mathrm{B} longrightarrow mathrm{C} ) ( Delta mathrm{H}=100 mathrm{kcal} ) and ( Delta mathrm{S}=0.050 mathrm{kcal} mathrm{K}^{-1} . ) If ( Delta mathrm{H} ) and ( Delta mathrm{S} ) are assumed to be constant over the temperature range, above what temperature will the reaction become spontaneous?

# For the reaction at ( 298 mathrm{K}, 2 mathrm{A}+mathrm{B} longrightarrow mathrm{C} ) ( Delta mathrm{H}=100 mathrm{kcal} ) and ( Delta mathrm{S}=0.050 mathrm{kcal} mathrm{K}^{-1} . ) If ( Delta mathrm{H} ) and ( Delta mathrm{S} ) are assumed to be constant over the temperature range, above what temperature will the reaction become spontaneous?

(A) ( 1000 mathrm{K} )

(B) ( 1500 mathrm{K} )

(C) ( 2000 mathrm{K} )

(D) ( 2500 mathrm{K} )

Solution

ΔC = 0

ΔH = TΔS = 0

ΔH = TΔS

(T= frac{ΔH}{ΔS})

= (frac{100}{0.050})

= (frac{100 times 10}{50})

= 2000k