A mixture containing `SiO_(2)`, NaCl and `NH_(4)Cl` is taken for separating the constituents . The suitable steps required for this are

Options

A. Sublimation-dissolution-filtration-crystallisation
B. Dissolution-filtration-crystallisation-distillation
C. Sublimation-evaporation-dissolution-decomposition
D. Dissolution-distillation-decomposition-evaporation.

Explanation

To separate the constituents of a mixture containing SiO₂, NaCl, and NH₄Cl, we can follow these steps:

### Step-by-Step Solution:

1. **Sublimation of NH₄Cl**:
- Heat the mixture gently. NH₄Cl will sublime, meaning it will change from a solid to a gas without passing through a liquid phase.
- As it sublimates, the gas will rise and can be collected on a cooler surface, where it will condense back into solid NH₄Cl.

2. **Dissolution of NaCl**:
- After removing NH₄Cl, the remaining mixture will contain SiO₂ and NaCl.
- Add water to the remaining solid mixture. NaCl is soluble in water, while SiO₂ is not.
- Stir the mixture to allow NaCl to dissolve completely in the water.

3. **Filtration**:
- Filter the mixture using filter paper.
- The solid SiO₂ will remain on the filter paper, while the NaCl solution will pass through into the filtrate.

4. **Evaporation of Water**:
- To recover NaCl from the solution, heat the filtrate to evaporate the water.
- As the water evaporates, NaCl will crystallize out of the solution.

5. **Collection of Products**:
- Collect the solid NH₄Cl from sublimation, the solid SiO₂ from filtration, and the crystallized NaCl from evaporation.

### Summary of Steps:
1. **Sublimation** of NH₄Cl.
2. **Dissolution** of NaCl in water.
3. **Filtration** to separate SiO₂.
4. **Evaporation** to obtain NaCl.

---