The reaction Br₂(g)→ 2Br(g)is spontaneous only at temperatures in excess of 1600°C.We can conclude that A)ΔH is + and ΔS is + for the reaction. B)ΔH is - and ΔS is + for the reaction. C)ΔG is + for all temperatures. D)ΔH is - and ΔS is - for the reaction. E)ΔH is + and ΔS is - for the reaction.

Question

Quizplus · Accepted Answer

For a reaction to be spontaneous at high temperatures but not at low temperatures, the enthalpy change (ΔH) must be positive, indicating that the reaction absorbs heat, and the entropy change (ΔS) must also be positive, indicating an increase in disorder. This combination means that the temperature must be high enough for the TΔS term to overcome the positive ΔH in the Gibbs free energy equation ΔG = ΔH - TΔS, making ΔG negative and the reaction spontaneous at high temperatures.

The Reaction Br2(g)→ 2Br(g)is Spontaneous Only at Temperatures in Excess

The Reaction Br₂(g)→ 2Br(g)is Spontaneous Only at Temperatures in Excess