Question Detail
Question
Given the thermochemical equation: 2NO₂(g) → 2NO(g) + O₂(g) ΔH = 114 kJ. What is the ΔH for the reaction NO(g) + ½O₂(g) → NO₂(g)?
Correct Answer
Option C is the correct answer.
Detailed Explanation
The target reaction is the reverse of half of the given reaction. Reverse: 2NO + O₂ → 2NO₂, ΔH = -114 kJ. Divide by 2: NO + ½O₂ → NO₂, ΔH = -57 kJ.
Hint
Reversing changes sign; halving halves ΔH.