`H_(2)(g) +Cl_(2)(g) rarr 2HCl(g) +185 kJ`. State whether this reaction is exo or endothermic and why?

Explanation

To determine whether the reaction \( H_2(g) + Cl_2(g) \rightarrow 2HCl(g) + 185 \, \text{kJ} \) is exothermic or endothermic, we can follow these steps:

### Step 1: Understand the definitions
- **Exothermic Reaction**: A reaction that releases heat energy to the surroundings. In such reactions, the energy of the products is lower than the energy of the reactants.
- **Endothermic Reaction**: A reaction that absorbs heat energy from the surroundings. In these reactions, the energy of the products is higher than the energy of the reactants.

### Step 2: Analyze the given reaction
The reaction is given as:
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