Question

Do as directed :

(a) Write the apparatus used and observations made in the experiment done to separate sand and salt from their mixture.

(b) Write the procedure followed and draw the diagram of the apparatus used in the experiment for separating a sublimating substance from a mixture.

Answer 1

Apparatus used: Funnel, test tube, beaker, burner, stand

Experiment: Dissolve the mixture of salt and sand in water. Salt, being soluble, will dissolve in water. Sand, on the other hand, will settle at the bottom of the solution. Salt solution can be separated from sand by decantation and filtration.

Observation: We are left only with salt solution. Salt can be separated from this solution by simple evaporation.

(b) The mixture of a sublimating substance, say ammonium chloride (NH₄Cl) and sand can be easily separated with the help of the following three processes:

1) Sublimation

2) Decantation and Filtration

3) Evaporation

Among all the three compounds, ammonium chloride is a sublimate.

Procedure: First, take the mixture in a china dish. Place this china dish on a tripod stand and cover the dish by inverting a funnel over it. Plug the top of the funnel with cotton to prevent the vapours of ammonium chloride from escaping into the atmosphere. Heat the china dish using a burner. On heating, the ammonium chloride sublimes. As a result, ammonium chloride gets separated from the sand and it solidifies on the cold walls of the funnel.