Page 14 - Chemistry - XI

EXPERIMENT - 4

Objective
To bore a hole in the cork and fi t a glass tube in the hole.

Materials Required
A cork, a cork borer set, glass tube, fl ask, glycerine, and water

Procedure
1. Selection of a proper cork: Select a cork which is free from cracks and holes having a size such that
the narrow end when pressed gently into the mouth of the fl ask fi ts one fourth of it into the fl ask.

2. Wetting the cork: Wet the cork with water and glycerine. If the cork is too hard, press it by some
heavy material for some time.
3. Selection of a proper borer: Select the borer of diameter slightly less than that of the outer diameter
of the glass tube to be fi tted.

4. Boring the hole in the cork:

a. Place a rubber cork on the table with its small end in the upward direction.
b. Hold the cork with the left hand and put a suitable borer dipped in solution in a position where hole
is to be drilled.
c. Hold the borer vertically and drill the cork by rotating the borer and applying pressure gently.

d. Add a few drops of glycerine solution into the boring tube to make the boring smooth and quicker.
e. Boring of the cork should be done from both sides of the cork so that the bore is vertical.

Place marked for boring

(a)

Glass tube Borer

(b) (c)

Fig. 4.1: (a) Marked cork (b) Choosing the borer (c) Boring process

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