Question

Explain why:
(a) An antacid tablet is taken when you suffer from acidity.
(b) Calamine solution is applied on the skin when an ant bites.
(c) Factory waste is neutralised before disposing it into the water bodies.

Answer 1

Hint : We take an antacid tablet to neutralise the excessive acid released in our stomach.When ant bites they inject formic acid into the skin which causes inflammation to the skin. Factory waste is neutralised before disposing it into the water bodies because it contains harmful acids.

Complete answer:
(a) In our stomach sometimes acid secrets when this happens we say that we have acidity , then we are advised by the doctor to take antacid tablets which contain mild bases like sodium bicarbonate which reacts with acid and neutralises it and forms salt and water.
(b) Calamine solution is applied on the skin when an ant bites because ants inject formic acid in our skin which causes itching and inflammation, calamine solution is a base. It is zinc carbonate ,hence it neutralises the effect of acid when applied on skin. Calamine is also useful in sunburn, poison ivy and other mild skin problems.
(c) Factory waste is neutralised before disposing it into water bodies because factory waste contains harmful chemicals and acids which are harmful for aquatic life as well as for humans so once its neutralised it turns to unharmful substance. Slaked lime which is a base is added to factory waste to neutralise it .

Note : In all the three statements we have seen that it is acid base reactions basically where base is added or applied to neutralise the harmful effect of acid . When acid base reacts it gives salt and water ,so this property of acid-base reaction is used in many medical and chemical uses.