Temporary hardness in water is due to which one of the following of Calcium and Magnesium ?

Options

A. Hydrogencarbonates
B. Carbonates
C. Chlorides
D. Sulphates

Explanation

### Step-by-Step Solution

1. **Understanding Temporary Hardness**:
- Temporary hardness in water is primarily caused by the presence of certain compounds. It is essential to know what these compounds are to identify the source of hardness.

2. **Identifying the Compounds**:
- Temporary hardness is mainly due to the presence of bicarbonates of calcium and magnesium. These compounds can also be referred to as hydrogen carbonates.

3. **Chemical Composition**:
- The chemical formulas for the bicarbonates are:
- Calcium bicarbonate: \( Ca(HCO_3)_2 \)
- Magnesium bicarbonate: \( Mg(HCO_3)_2 \)

4. **Effect of Temporary Hardness**:
- Temporary hardness affects the behavior of soap in water. When soap is used in hard water, it does not form lather effectively due to the presence of these bicarbonates.

5. **Removal of Temporary Hardness**:
- Temporary hardness can be removed by boiling the water. When water is boiled, the bicarbonates decompose, leading to the precipitation of calcium and magnesium carbonates, thus softening the water.

6. **Conclusion**:
- Therefore, the correct answer to the question is that temporary hardness in water is due to the presence of calcium and magnesium bicarbonates.

### Final Answer:
Temporary hardness in water is due to the presence of calcium and magnesium bicarbonates.

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