Question

question 1 20 pts a thermochemical reaction of ammonia formation is: 3 h₂(g) + n₂(g) ⇌ 2 nh₃(g) δh = -86 \frac{kj}{mol} (estimated value). which of the following statements is incorrect? \bigcirc the reaction is reversible. \bigcirc energy is released as heat when the reaction proceeds as written (a forward reaction). \bigcirc it is a redox reaction. \bigcirc the forward reaction is endothermic, and the reverse reaction is exothermic.

Explanation:

1. Analyze the reversible nature: The reaction uses a double - headed arrow ($

ightleftharpoons$), which indicates that the reaction is reversible. So the statement "The reaction is reversible" is correct.

1. Analyze the heat change: The enthalpy change $\Delta H=- 86\frac{kJ}{mol}$. A negative $\Delta H$ means that the reaction releases heat when proceeding in the forward direction (as written). So the statement "Energy is released as heat when the reaction proceeds as written (a forward reaction)" is correct.
2. Analyze redox nature: In the reaction $3H_{2}(g)+N_{2}(g)

ightleftharpoons2NH_{3}(g)$, the oxidation state of $H$ in $H_{2}$ is 0 and in $NH_{3}$ is + 1 (oxidation), and the oxidation state of $N$ in $N_{2}$ is 0 and in $NH_{3}$ is - 3 (reduction). So it is a redox reaction, and the statement "It is a redox reaction" is correct.

1. Analyze endothermic/exothermic: For a reaction, if $\Delta H\lt0$, the forward reaction is exothermic (releases heat), and the reverse reaction (which has $\Delta H = + 86\frac{kJ}{mol}$) is endothermic (absorbs heat). So the statement "The forward reaction is endothermic, and the reverse reaction is exothermic" is incorrect.

Answer:

The forward reaction is endothermic, and the reverse reaction is exothermic.