Mixing of solutions of `BaCl_(2) and Na_(2)SO_(4)` results in the formation of a precipitate of `BaSO_(4)` only if.......greater than......... .

Answer

To solve the question regarding the mixing of solutions of BaCl₂ and Na₂SO₄ resulting in the formation of a precipitate of BaSO₄, we will follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
- We have two solutions: BaCl₂ (barium chloride) and Na₂SO₄ (sodium sulfate).
- When mixed, these salts dissociate completely into their ions:
- BaCl₂ dissociates into Ba²⁺ and 2Cl⁻ ions.
- Na₂SO₄ dissociates into 2Na⁺ and SO₄²⁻ ions.

2. **Identify the Product**:
- The product we are interested in is BaSO₄ (barium sulfate), which forms when Ba²⁺ ions react with SO₄²⁻ ions.

3. **Understand Precipitation**:
- A precipitate forms when the product of the concentrations of the ions exceeds a certain threshold known as the solubility product (Ksp).
- The reaction can be represented as:
\[ \text{Ba}^{2+} + \text{SO}_4^{2-} \rightarrow \text{BaSO}_4 (s) \]

4. **Define Ionic Product and Solubility Product**:
- The ionic product (IP) is defined as the product of the concentrations of the ions in solution:
\[ \text{IP} = [\text{Ba}^{2+}] \times [\text{SO}_4^{2-}] \]
- The solubility product (Ksp) is a constant that represents the maximum product of the concentrations of the ions in a saturated solution at a given temperature.

5. **Condition for Precipitation**:
- A precipitate of BaSO₄ will form only when the ionic product exceeds the solubility product:
\[ \text{IP} > \text{Ksp} \]

6. **Fill in the Blanks**:
- Therefore, the answer to the question is:
- Mixing of solutions of BaCl₂ and Na₂SO₄ results in the formation of a precipitate of BaSO₄ only if **ionic product** is greater than **solubility product**.

### Final Answer:
Mixing of solutions of BaCl₂ and Na₂SO₄ results in the formation of a precipitate of BaSO₄ only if **ionic product** > **solubility product**.