Desalination of sea water can be done by

Options

A. Filtration
B. Osmosis
C. Reverse osmosis
D. Diffusion

Answer

### Step-by-Step Solution for Desalination of Sea Water

1. **Understanding Desalination**: Desalination is the process of removing salt and other impurities from seawater to produce fresh water. This is essential in areas where fresh water is scarce.

2. **Filtration**: The first step often mentioned is filtration. However, in the case of seawater, it primarily contains dissolved salts rather than solid particles. Therefore, simple filtration is not effective for desalination.

3. **Osmosis**: Osmosis is the movement of solvent molecules from an area of lower solute concentration to an area of higher solute concentration through a semipermeable membrane. However, this process alone does not desalinate seawater.

4. **Reverse Osmosis (RO)**: The most effective method for desalinating seawater is reverse osmosis. In this process:
- Seawater is pushed through a semipermeable membrane under high pressure.
- The membrane allows water molecules to pass through but blocks salt and other impurities.
- As a result, fresh water accumulates on one side of the membrane while the salt remains on the other side.

5. **Conclusion**: Therefore, the correct method for desalinating seawater is reverse osmosis.

### Final Answer
Desalination of seawater can be done by **reverse osmosis (RO)**.

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