`BaCl_(2(aq)) + Na2SO_(4(aq)) to BaSO_(4(s)) + 2NaCl_((aq))`
The types of reaction are
(1) displacement (2) precipitation
(3) combination
(4) double displacement

Options

A. (1) and (3)
B. (1), (2) and (3)
C. (2) and (3)
D. (2) and ( 4).

Answer

To determine the type of reaction represented by the equation:

\[ \text{BaCl}_2(aq) + \text{Na}_2\text{SO}_4(aq) \rightarrow \text{BaSO}_4(s) + 2\text{NaCl}(aq) \]

we will analyze the reaction step by step.

### Step 1: Identify the Reactants and Products
The reactants in this reaction are:
- Barium chloride (\( \text{BaCl}_2 \))
- Sodium sulfate (\( \text{Na}_2\text{SO}_4 \))

The products formed are:
- Barium sulfate (\( \text{BaSO}_4 \)), which is a solid (indicated by (s))
- Sodium chloride (\( \text{NaCl} \)), which remains in aqueous solution (indicated by (aq))

### Step 2: Determine the Type of Reaction
To classify the type of reaction, we need to consider the following:

1. **Displacement Reaction**: This involves one element displacing another in a compound. This is not applicable here as both reactants are ionic compounds.

2. **Double Displacement Reaction**: This occurs when the ions of two compounds exchange places to form two new compounds. In our reaction, the barium ions (\( \text{Ba}^{2+} \)) from barium chloride exchange with sodium ions (\( \text{Na}^+ \)) from sodium sulfate, resulting in barium sulfate and sodium chloride. Therefore, this reaction is classified as a double displacement reaction.

3. **Precipitation Reaction**: A precipitation reaction occurs when two soluble salts react to form an insoluble salt. In this case, barium sulfate (\( \text{BaSO}_4 \)) is formed, which is insoluble in water and precipitates out of the solution. Thus, this reaction is also classified as a precipitation reaction.

4. **Combination Reaction**: This involves two or more reactants combining to form a single product. This is not applicable here as we have multiple products.

### Conclusion
The reaction can be classified as both a double displacement reaction and a precipitation reaction. Therefore, the correct options are:
- (2) Precipitation
- (4) Double Displacement

### Final Answer
The types of reaction are:
- (2) Precipitation
- (4) Double Displacement