Separation of Common Salt, Sand, and Iron Filling Mixture

To separate a mixture of common salt, sand, and iron filings, we can use various physical separation techniques based on the differences in their physical properties. These techniques include filtration, magnetic separation, and evaporation.

Filtration

The first step in separating the mixture is to use filtration to separate the sand from the mixture. Filtration is a technique that uses a porous material, such as filter paper or a filter funnel, to separate insoluble solid particles from a liquid or a mixture.

1. Set up a filtration apparatus by placing a filter paper in a filter funnel, which is attached to a conical flask.
2. Carefully pour the mixture into the funnel, allowing the liquid (salt solution) to pass through the filter paper while retaining the solid particles (sand) on the filter paper.
3. The liquid collected in the conical flask is the salt solution, while the sand remains on the filter paper.

Magnetic Separation

The next step is to separate the iron filings from the remaining salt solution. Magnetic separation is a technique that uses a magnetic force to separate magnetic materials from non-magnetic ones.

1. Use a magnet and pass it over the remaining mixture in the conical flask.
2. The iron filings will be attracted to the magnet and can be easily separated from the mixture.
3. Remove the iron filings from the magnet and collect them separately.

Evaporation

The final step involves separating the salt from the salt solution obtained from the filtration process. Evaporation is a technique that involves heating a solution to evaporate the solvent and leave behind the dissolved solute.

1. Pour the salt solution into an evaporating dish.
2. Heat the evaporating dish gently using a Bunsen burner or any other heat source.
3. As the solvent (water) evaporates, the salt will start to crystallize and form solid particles.
4. Once all the water has evaporated, the salt crystals can be collected from the evaporating dish.

Conclusion

By using a combination of filtration, magnetic separation, and evaporation techniques, we can successfully separate the mixture of common salt, sand, and iron filings. Filtration helps in separating the sand from the mixture, magnetic separation helps in separating the iron filings from the remaining salt solution, and evaporation helps in obtaining pure salt from the salt solution. These physical separation techniques are effective in separating the components of a mixture based on their physical properties, allowing us to obtain the individual components in their pure form.