020 DISTILLED WATER FOR LABORATORY EXPERIMENTS

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020 DISTILLED WATER FOR LABORATORY EXPERIMENTS
Several physiology experiments require distilled
water. The same can be prepared at school using
solar energy.
MATERIALS NEEDED
Glass trough, Glass tumbler Polythene sheet Food
colouring Some clean pebbles and water
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Take water in the trough and add some food colour
to it. Stir well for a good mixing of the colour.
Take the glass tumbler and add a few clean
pebbles into it for weight.
3
Place this tumbler in the trough. The pebbles
keep the tumbler in position, else the glass may
float or fall. Cover the unit with polythene
sheet, but make sure the middle portion of the
sheet dips at the tumbler. use pebbles to cause
this depression. Keep this set-up in the sun.
Water evaporates, the droplets get attached to
the sheet, flow down to the depressed area and
drip into the tumbler.
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coloured water
clean water
After some time, remove the polythene sheet, take
the tumbler out and observe water in the tumbler.
It is clean distilled water. Compare with water
in the trough. This water can be used to prepare
reagents in the laboratories.