For the reaction `2NH_(3) hArr N_(2) + 3H_(2)` equilibrium constant at `25^(@)`C and `400^(@)`C and 3.5 and 35 respectively. This means that the forward reaction is:

Options

A. Exothermic
B. endothermic
C. Exorgic
D. Onpredic table

Answer

To determine whether the forward reaction \(2NH_3 \rightleftharpoons N_2 + 3H_2\) is endothermic or exothermic based on the given equilibrium constants at different temperatures, we can follow these steps:

### Step 1: Write down the equilibrium constants at the given temperatures.
- At \(25^\circ C\), the equilibrium constant \(K_{25} = 3.5\)
- At \(400^\circ C\), the equilibrium constant \(K_{400} = 35\)

### Step 2: Analyze the change in equilibrium constant with temperature.
- We observe that as the temperature increases from \(25^\circ C\) to \(400^\circ C\), the equilibrium constant increases from \(3.5\) to \(35\).

### Step 3: Relate the change in equilibrium constant to the nature of the reaction.
- According to Le Chatelier's principle, if the equilibrium constant increases with an increase in temperature, the reaction must absorb heat. This indicates that the forward reaction is endothermic.

### Step 4: Conclude the nature of the reaction.
- Since the equilibrium constant increases with temperature, we conclude that the forward reaction \(2NH_3 \rightleftharpoons N_2 + 3H_2\) is an endothermic reaction.

### Final Answer:
The forward reaction is endothermic.

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