Dear student ,
a) Antacid tablets mainly consist of milk of magnesia or magnesium hydroxide, which neutralises the excess hydrochloric acid present in the stomach, thus reducing acidity. Hence, a person suffering from acidity takes antacid tablets.
b) Quicklime (calcium oxide), slaked lime (calcium hydroxide) and chalk (calcium carbonate) are all basic in nature. These are added to the soil when it is acidic and hence unsuitable for cultivation. Addition of these substances to acidic soil would increase the pH of the soil, thereby neutralising the excess of acid and optimizing the pH range most suitable for healthy growth of plants.
c) Wasp sting contain venom which is alkaline in nature. Its alkalinity can be neutralized by using acetic acid or vinegar.