Page 24 - Curriculum Visions Dynamic Book

Calcium hydroxide
Calcium hydroxide is a white solid. You may have seen cartons containing it in a garden shop under the name of “slaked lime” or “hydrated lime,” where it is sold as a soil conditioner.
Calcium hydroxide can be formed by adding water to calcium oxide. The effect of this is shown on this page.
It is a reaction that gives out considerable amounts of heat.
Another way of obtaining calcium hydroxide is shown on page 7, but calcium is too expensive to obtain as a metal for widespread industrial use.
 In the demonstration on this page, a block of calcium oxide (quicklime) is placed on a tray. Water is now poured onto one side of the block. This is so that changes that happen to the side in contact with water can then be compared to the original state of the calcium oxide, in its dry form.
The reaction is spectacular. The water soaks into the calcium oxide and disappears. The part of the
block of quicklime in contact with the
water gets extremely hot, swells
and gives
off steam. (There is a picture of the original solid on page 21.)
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