Question Detail
Question
Reversing 2H2O(l) -> 2H2(g) + O2(g) gives ΔH = __________ kJ.
Correct Answer
Option B is the correct answer.
Detailed Explanation
The forward reaction (electrolysis) is endothermic. ΔH for 2H2O(l) -> 2H2(g) + O2(g) is +572 kJ (twice +286, with sign reversed from formation).
Hint
Reverse of formation, and scaled by 2.