In order to separate a mixture of sand and salt, which one of the following four sequences of processes has to be used?

Correct option is C

The correct answer is Sedimentation, decantation, filtration, evaporation.
Evaporation, Sedimentation, Decantation, and Filtration are the separating techniques used in our day-to-day life. We can find a mixture of components and to obtain a pure component we need to adopt a few techniques for purification and separation.
Sedimentation: It is defined as the separation process in which solids are separated from the liquid. All the solids settle down at the bottom of a beaker and on top, a clear layer of liquid is obtained. Sedimentation is a process by which heavier impurities present in liquid settle down at the bottom of the container containing the mixture. The process takes some amount of time. Example: In the sand and salt mixture, the sand settles at the bottom of the beaker to form saltwater at the top.
Decantation: Decantation is a process to separate mixtures by removing a liquid layer from the solids deposited from a solution. This is done by pouring out the clear upper layer of liquid. Example: After the sand settling at the bottom the relatively clean water containing salt is poured out of the beaker. Filtration: It is defined as the separation process in which insoluble impurities are separated from the solution.
Filtration is done with the help of filter paper. Example: The above mixture filtration is used here to remove any solid suspended sand particles from the liquid.
Evaporation: It is the process by which water changes from a liquid to a gas or vapour. Boiling is the process in which a liquid is converted into its vapour when heated to its boiling point. In the evaporation separation technique, the water evaporates leaving behind the soluble portion. Example: In the above mixture, the water is evaporated leaving behind salt crystals.
Thus, in order to separate a mixture of sand and salt, the four sequences of processes to be used are sedimentation, decantation, filtration and evaporation.