Separating Salt from Water: Evaporation

Evaporation is the process by which a liquid, in this case, water, changes into a gas and leaves behind any dissolved substances, such as salt. It is one of the most common methods used to separate salt from water.

Here is a detailed explanation of how evaporation separates salt from water:

1. Initial Mixture:
- Saltwater is a mixture of salt (solute) and water (solvent).
- The salt particles are dissolved in the water, making it a homogeneous mixture.

2. Heating the Mixture:
- The saltwater mixture is heated in a container, causing the water to evaporate.
- Evaporation occurs when the heat energy provided increases the kinetic energy of water molecules, enabling them to escape the liquid phase and enter the gaseous phase.

3. Water Vapor Formation:
- As the water evaporates, it turns into water vapor, a gaseous state.
- Salt particles do not evaporate and remain behind in the container.
- The vapor may condense back into liquid form when it comes into contact with a cooler surface or cools down.

4. Collection:
- The water vapor can be collected using a condensation process, where the vapor is cooled and converted back into liquid water.
- This collected water is now separate from the salt.

5. Salt Residue:
- The salt left behind in the container is now separated from the water.
- It can be collected and used or further processed as desired.

Evaporation is an effective method for separating salt from water because the salt particles are too large to evaporate along with the water molecules. As the water evaporates, it leaves behind the salt in its solid form.

This process is similar to what happens when seawater evaporates naturally under the sun, leaving behind salt crystals. In industrial settings, evaporation is often used on a larger scale to produce salt from seawater for various purposes.

In conclusion, the correct answer to the question is option 'C' - Evaporation. By heating the saltwater mixture and allowing the water to evaporate, we can separate salt from water.