Which of the following reactions releases heat to the surroundings as it proceeds to completion?
I. C (coal) + H₂O (g) + 130 KJ→CO (g) + H₂ (g)
II. 2 NO₂ (g) →N₂O₄ (exothermic)
III. 2 H₂ (g) + O₂ (g) →2 H₂O (g) D H _rxn = - 572 kJ

Question

Quizplus · Accepted Answer

Reactions that release heat to the surroundings are exothermic. Reaction II is explicitly labeled as exothermic, and Reaction III has a negative ΔH, indicating it releases heat. Reaction I, however, requires the input of 130 KJ, making it endothermic.

Which of the Following Reactions Releases Heat to the Surroundings