Barium can displace which element from its sulphate?

Options

A. Sodium
B. Caesium
C. Aluminium
D. Hydrogen

Explanation

To determine which element can be displaced by barium from its sulfate, we need to consider the reactivity series of metals. The reactivity series is a list of metals arranged in order of decreasing reactivity. A more reactive metal can displace a less reactive metal from its compound.

### Step-by-Step Solution:

1. **Understand the Question**: We need to find out which element can be displaced by barium from its sulfate.

2. **Identify the Elements**: The options given are sodium, cesium, aluminum, and hydrogen.

3. **Analyze Cesium**: Cesium is a highly reactive and radioactive element. Due to its instability and high reactivity, barium cannot displace cesium from its sulfate.

4. **Analyze Hydrogen**: Hydrogen is much less reactive than barium. Since barium is more reactive, it cannot displace hydrogen from its sulfate.

5. **Compare Sodium and Aluminum**:
- Sodium is a highly reactive metal and is placed above aluminum in the reactivity series.
- Aluminum is less reactive than sodium.

6. **Determine the Most Reactive Element**: Since sodium is more reactive than aluminum, it is the element that can be displaced by barium.

7. **Conclusion**: Barium can displace sodium from its sulfate. The reaction can be represented as:
\[ \text{BaSO}_4 + \text{NaCl} \rightarrow \text{Barium Chloride} + \text{Sodium Sulfate} \]
Thus, the answer is sodium.

### Final Answer:
Barium can displace **sodium** from its sulfate.

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