Question

Give reasons:
(i) Use of a mild base like baking soda provides relief on the area stung by honeybee.
(ii) Baking powder is added to make the cakes spongy and soft.
(iii) The colour of blue copper sulphate crystals changes to white on heating.

Answer 1

1. Bee sting leaves Methanoic acid which causes pain and irritation .use of mild base like baking soda on the sting area gives relief. stinging hair of nettle leaves inject Methanoic acid causing burning pain .
2. Baking powder is a mild edible acid .When it is heated or mixed in water it releases carbon dioxide which causes bread or cake to rise making them soft fluffy and spongy .
3. When blue copper sulphate crystals are heated it losses water of crystlasaiton and changes to white.