Question

You are provided with a mixture of sand, oil, salt, and water. Write the steps involved in separating sand, soil, salt, and water from the given mixture along with the activity and a labeled diagram.

Answer 1

Mixture:

• When two or more substances are combined together without resulting in a change in their individual properties it is known as a mixture.

Separation of mixture:

• The given mixture contains sand, salt, oil, and water thus the separation can be done in a series of steps using various physical and other methods.

Steps of separating the given mixture:

1. Separating the oil from the rest of the components in the mixture:

• The oil and water in the mixture are an example of immiscible liquids (liquids that do not mix with one another resulting in separate layers of the two liquids) and thus can be separated by means of a simple physical method known as Decantation.
• Decantation is a physical method that can be employed to separate immiscible liquids.
• In this method, the upper layer(here, oil) can be separated from the bottom layer (here, water) by simply pouring it into another vessel.
• After decanting the oil we are left with a mixture containing salt, sand, and water.
• 

2. Separation of sand from the remaining mixture:

• Sand particles might be coarse or a little fine which can be easily separated out using the Filtration method.
• Filtration is the method of separating insoluble solid particles from liquid with the help of filter paper.
• The mixture is poured through a filter paper and the sand particles are left on the paper whereas the liquid mixture (salt solution) passes through it into another container.

3. Separating salt from the remaining mixture of salt and water:

• Salt and water form a homogenous solution (salt completely dissolves in water) thus it cannot be separated by mechanical method.
• The salt can be separated from water by evaporation:
• Evaporation is the process by which the liquid is converted to its gaseous state.
• For this heat the salt solution, will evaporate the water leaving behind salt from the mixture.

Thus, the given mixture of salt, sand, oil, and water is separated using decantation, filtration, and evaporation methods.