Question

(a) write the separation of the components of mixture of sand, common salt and ammonium chloride.

(b) why do we use glycerin instead of water to prepare a temporary mount?

Answer 1

(a)

The Procedure:

Preparing the mixture of ammonium chloride, sand and common salt:

Take a small quantity of a mixture of sand, common salt and ammonium chloride in a china dish.

Separation of Ammonium Chloride:

Real Lab Procedure:

• Place the china dish on a wire gauze that is placed over a tripod stand.
• Cover the china dish with an inverted glass funnel and plug in a little cotton at the opening of the stem of the funnel.
• On heating the mixture in the china dish, white fumes evolve and rise inside the funnel.
• Stop heating when the white fumes stop rising and allow the funnel to cool.
• After cooling, remove the funnel from the china dish and using a spatula, transfer the solid ammonium chloride sticking on the walls of the funnel into a watch glass.

Inference:

• Ammonium chloride sublime and can be separated from the mixture of salt and sand by the process of sublimation.

Separation of sand particles:

Real Lab Procedure:

• Transfer the contents of the china dish into a beaker and pour some distilled water into it and stir it well using a glass rod.
• Filter the contents of the funnel into another beaker.
• Transfer the sand particles left on the filter paper into a watch glass using a spatula.

Inference:

Sand can be separated from the mixture of sand and salt by dissolving salt in water and then by filtration.

Separation of salt:

Real Lab Procedure:

• Transfer the filtrate in the beaker into a china dish and strongly heat it.
• After some time, the salt is left as a residue in the china dish; transfer it into another watch glass.
• Finally label the three components that have been separated from the mixture.

Inference:

Salt can be separated through the process of evaporation.

(b) We use glycerine for mounting onion feel for expelling bubbles which can be found between slides.

Glycerin is a natural compound referred to all the more formally as glycerol. Its normal sources are animal fat and vegetable oil.

Glycerine is a good dried out agent. It avoids the drying of the specimen. Additionally, glycerine has a tendency to reflect light because of its refractive nature. Because of it, the picture shows up clearer under the magnifying lens. Because of these reasons, glycerine is utilized while setting up an impermanent mount of onion peel.