Siddharth dissolved a mixture into water and then filtered it. Solid `X` was left behind as residue in the filter paper and solid `Y` was obtained by evaporating the filtrate to dryness. `X` and `Y` could be respectively

Options

A. Sodium hydroxide and calcium carbonate
B. Calcium chloride and sodium carbonate
C. Calcium carbonate and sodium chloride
D. Sodium carbonate and calcium chloride

Explanation

To solve the question, we need to analyze the process described and identify the solids involved.

### Step-by-Step Solution:

1. **Understanding the Mixture**: Siddharth has a mixture that he dissolved in water. When a mixture is dissolved, it can contain both soluble and insoluble components.

2. **Filtration Process**: After dissolving the mixture, Siddharth filtered it. During filtration, the insoluble components remain on the filter paper, while the soluble components pass through and are collected in the filtrate.

3. **Identifying Solid X**: The solid X that is left behind on the filter paper is an insoluble substance. Based on the context, we can assume that solid X is calcium carbonate (CaCO3), which does not dissolve in water and thus remains as residue.

4. **Evaporation of Filtrate**: The liquid that passed through the filter paper is the filtrate. Siddharth then evaporated this filtrate to dryness, which means he removed the water, leaving behind any soluble substances that were present.

5. **Identifying Solid Y**: Solid Y, obtained by evaporating the filtrate, is a soluble substance. In this case, it is likely sodium chloride (NaCl), which dissolves in water and forms crystals upon evaporation.

6. **Conclusion**: Therefore, we can conclude that:
- Solid X (residue on filter paper) is calcium carbonate (CaCO3).
- Solid Y (obtained from evaporating the filtrate) is sodium chloride (NaCl).

### Final Answer:
Solid X is calcium carbonate (CaCO3) and solid Y is sodium chloride (NaCl).

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