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SAI International School
Subject-Chemistry
Class-VII
Topic-Acids, Bases and Salts
Sub topic-Neutralisation reaction in daily life
LESSON NOTES
1. Insect sting: The sting of an ant or a bee is painful because of
secretion of formic acid from the mouth of the insect. To get relief
from the pain we can apply baking soda on the affected area.
Baking soda neutralises the acid and we get instant relief. On the
other hand, a wasp sting is basic in nature, so we have to wash it
with vinegar (acidic) to get relief.
2. Preventing tooth decay: Some acids are produced in our mouth
which causes tooth decay. To prevent it we brush our teeth with
toothpastes which contain bases. Hence neutralisation reactions
take place in our mouth preventing tooth decay.
3. Acidity in our stomach: Hydrochloric acid is produced in our
stomach. Excess hydrochloric acid can cause acidity. To neutralise
this we have to take in antacid tablets (like Milk of Magnesia) and
get relief from pain.
4. Treating the soil: Plants grow best in neutral soil. Use of excessive
fertilisers can make the soil either acidic or basic. Depending upon
the nature of the soil they are treated with slaked lime or with
composted manure to neutralise the soil.
5. Treating wastes from factories: When acidic wastes from factories
are disposed off in rivers, they make the river water acidic, thus
causing harm to aquatic life. To prevent this, the acidic wastes are
neutralised with bases before disposing off to rivers.
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