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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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