For the reaction
c(s) + h2o(g) ? co(g) + h2 (g) δh∘=131.3kj/mol and δs∘=127.6j/k⋅mol at 298k. at temperatures greater than ∘c this reaction is spontaneous under standard conditions.

At temperatures greater than 756 °C this reaction is spontaneous under standard conditions.

Explanation:

Let's consider the following reaction.

C(s) + H₂O(g) ⇄ CO(g) + H₂(g)

The reaction is spontaneous when the standard Gibbs free energy ΔG° < 0. ΔG° is related to the standard enthalpy of the reaction (ΔH°) and the standard entropy of the reaction (ΔS°) through the following expression.

ΔG° = ΔH° - T.ΔS°

If ΔG° < 0

ΔH° - T.ΔS° < 0

ΔH° < T.ΔS°

T >  ΔH°/ΔS° = (131.3 × 10³ J/mol)/(127.6 J/K.mol) = 1029 K

The temperature in Celsius is:

°C = K - 273.15 = 1029 - 273.15 = 756 °C

i think it's c. i'm not sure but i think so.