Heat of solution of `BaCl_(2).2H_(2)O=200 kJ mol^(-1)`
Heat of hydration of `BaCl_(2)=-150 kJ mol^(-1)`
Hence heat of solution of `BaCl_(2)` is

Options

A. `350KJmol^(-1)`
B. `50KJmol^(-1)`
C. `-350KJmol^(-1)`
D. none of these

Explanation

To find the heat of solution of \( \text{BaCl}_2 \), we will use the given information about the heat of solution of \( \text{BaCl}_2 \cdot 2\text{H}_2\text{O} \) and the heat of hydration of \( \text{BaCl}_2 \).

### Step-by-Step Solution:

1. **Identify the given data:**
- Heat of solution of \( \text{BaCl}_2 \cdot 2\text{H}_2\text{O} = +200 \, \text{kJ mol}^{-1} \)
- Heat of hydration of \( \text{BaCl}_2 = -150 \, \text{kJ mol}^{-1} \)

2. **Write the reaction for the heat of solution of \( \text{BaCl}_2 \cdot 2\text{H}_2\text{O} \):**
\[ \text{BaCl}_2 \cdot 2\text{H}_2\text{O} (s) \rightarrow \text{Ba}^{2+} (aq) + 2\text{Cl}^- (aq) + 2\text{H}_2\text{O} (l) \]
- For this reaction, the enthalpy change \( \Delta H_1 = +200 \, \text{kJ mol}^{-1} \).

3. **Write the reaction for the heat of hydration of \( \text{BaCl}_2 \):**
\[ \text{BaCl}_2 (s) + 2\text{H}_2\text{O} (l) \rightarrow \text{Ba}^{2+} (aq) + 2\text{Cl}^- (aq) \]
- For this reaction, the enthalpy change \( \Delta H_2 = -150 \, \text{kJ mol}^{-1} \).

4. **Combine the two reactions:**
- The overall reaction for the dissolution of \( \text{BaCl}_2 \) can be derived from the two reactions above. We can add the two equations:
\[ \text{BaCl}_2 \cdot 2\text{H}_2\text{O} (s) \rightarrow \text{Ba}^{2+} (aq) + 2\text{Cl}^- (aq) + 2\text{H}_2\text{O} (l) \quad (\Delta H_1) \]
\[ \text{BaCl}_2 (s) + 2\text{H}_2\text{O} (l) \rightarrow \text{Ba}^{2+} (aq) + 2\text{Cl}^- (aq) \quad (\Delta H_2) \]

5. **Calculate the heat of solution of \( \text{BaCl}_2 \):**
- The heat of solution of \( \text{BaCl}_2 \) can be calculated using the formula:
\[ \Delta H = \Delta H_1 + \Delta H_2 \]
- Substituting the values:
\[ \Delta H = 200 \, \text{kJ mol}^{-1} + (-150 \, \text{kJ mol}^{-1}) = 200 - 150 = 50 \, \text{kJ mol}^{-1} \]

6. **Conclusion:**
- The heat of solution of \( \text{BaCl}_2 \) is \( +50 \, \text{kJ mol}^{-1} \).

### Final Answer:
The heat of solution of \( \text{BaCl}_2 \) is \( +50 \, \text{kJ mol}^{-1} \).