Which one of the following reactions would you expect to have the lowest $\Delta$S^$\circ$ A) CH₄(g) + 2O₂(g) $\rarr$ CO₂(g) + 2H₂O(g) B) C₂H₂(g) + ⁵/₂O₂(g) $\rarr$ 2CO₂(g) + H₂O(g) C) C₂H₄(g) + O₂(g) $\rarr$2CO₂(g) + 2H₂O(g) D) C₂H₆(g) + ⁷/₂O₂(g) $\rarr$ 2CO₂(g) + 3H₂O(g)

Question

Quizplus · Accepted Answer

The ΔH value is the lowest for reaction B because it involves weaker bonds being broken and formed compared to the other reactions. Specifically, in reaction B, the C-H bond and the S-O bond are broken and the C=O bond is formed, which are all relatively weak compared to the bonds involved in the other reactions.

Which One of the Following Reactions Would You Expect to Have