The amount of heat evolved when 0.50 mole of HCl is mixed with 0.30 mole of NaOH solution is

Options

A. 57.1 kJ
B. 28.55 kJ
C. 11.42 kJ
D. 17.13 kJ

Explanation

To solve the problem of the amount of heat evolved when 0.50 moles of HCl are mixed with 0.30 moles of NaOH, we can follow these steps:

### Step-by-Step Solution:

1. **Write the Balanced Chemical Equation**:
The reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH) can be represented as:
\[ \text{HCl} + \text{NaOH} \rightarrow \text{NaCl} + \text{H}_2\text{O} \]
This equation shows that one mole of HCl reacts with one mole of NaOH to produce one mole of NaCl and one mole of water.

2. **Identify the Limiting Reagent**:
We have 0.50 moles of HCl and 0.30 moles of NaOH. Since the reaction requires a 1:1 mole ratio, we need to determine which reactant will be consumed first (the limiting reagent).
- HCl available: 0.50 moles
- NaOH available: 0.30 moles

Since we have less NaOH (0.30 moles), NaOH is the limiting reagent.

3. **Calculate the Amount of Heat Evolved**:
According to the data provided, the heat evolved when one mole of H+ ions reacts is -57.1 kJ (the negative sign indicates that heat is released).
- Since NaOH provides 0.30 moles of OH- ions, it will react with 0.30 moles of H+ ions from HCl.
- Therefore, the amount of heat evolved when 0.30 moles of H+ ions react is calculated as follows:
\[ \text{Heat evolved} = 57.1 \, \text{kJ/mol} \times 0.30 \, \text{mol} = 17.13 \, \text{kJ} \]

4. **Final Answer**:
The amount of heat evolved when 0.50 moles of HCl are mixed with 0.30 moles of NaOH is **17.13 kJ**.