1.Give reasons for the following:
(a) Only one half of water molecule is shown in the formula of Plaster of Paris.
(b) Sodium hydrogen carbonates is used as an antacid.
(C) On strong heating, blue coloured copper sulphate crystals turn white.
{CBSE 2020}
Answers
Answer:
1. The actual formula of Plaster of Paris is
which means that one molecule of
is associated with two molecules of
The formula is simplified and written as
<br> (b) Sodium hydrogen carbonate is an essential constituent of antacids because it neutralises the effect of hydrochloric acid which is released in the stomach. That is way it is called antacid. <br>
2. Sodium bicarbonate reduces stomach acid. It is used as an antacid to treat heartburn, indigestion, and upset stomach. Sodium bicarbonate is a very quick-acting antacid. It should be used only for temporary relief.
3. The colour of hydrated copper sulphate CuSO4. 5H2O is blue that turns into white, when heated at high temperature in a test tube, due to the loss of water molecules from copper sulphate.