The amount of heat liberated when one mole of `NH_(4)OH` reacts with one mole of HCl is

Options

A. 13.7 Kcal
B. More than 13.7 Kcal
C. Less than 13.7 Kcal
D. Cannot be prodicted

Answer

To determine the amount of heat liberated when one mole of NH₄OH reacts with one mole of HCl, we can follow these steps:

### Step 1: Identify the Reaction
When NH₄OH (ammonium hydroxide) reacts with HCl (hydrochloric acid), the reaction can be represented as:
\[ \text{NH}_4\text{OH} + \text{HCl} \rightarrow \text{NH}_4\text{Cl} + \text{H}_2\text{O} \]

### Step 2: Understand the Nature of the Reactants
- HCl is a strong acid, which means it completely dissociates in solution.
- NH₄OH is a weak base, which means it does not completely dissociate in solution.

### Step 3: Heat of Reaction for Strong Acid and Strong Base
For a reaction between a strong acid and a strong base, the heat released is approximately -13.7 kcal when one mole of water is formed. This value represents the heat of neutralization.

### Step 4: Adjust for Weak Base
Since NH₄OH is a weak base, the reaction will not proceed to completion as it would with a strong base. Therefore, the heat released will be less than -13.7 kcal. This is because some energy is required to dissociate NH₄OH into its ions (NH₄⁺ and OH⁻), which absorbs energy.

### Step 5: Conclusion
Thus, the overall heat released when one mole of NH₄OH reacts with one mole of HCl will be less than -13.7 kcal.

### Final Answer
The amount of heat liberated is less than -13.7 kcal.

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