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Answer the following questions : (i) ...

Answer the following questions :
(i) Why do soaps not work in hard water?
(ii) What are the main constituents of dettol?
(iii) How do antiseptics differ from disinfectants?

Text Solution

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(i) Hard water contains calcium and magnesium ions. These ions form insolubIe calcium and magnesium soaps respectively when sodium or potassium soaps a re dissolved in hard water.
`underset("Sope")(2C_17H_35)COONa+CaCl_2to2NaCl+underset("stearate (Soap)")underset("Insoluble calcium")((C_17H_35COO)_2)Ca`
These insoluble soaps separate as scum in water and are useless as cleansing agents.
(ii) The main constituent of dettol are chloroxylenol and terpineol of in a suitable solvent.
(iii) Antiseptics are the chemical substances which are used to either kill or prevent the growth of micro-organisms. These are not harmful to living tissues and can be safely applied on wounds, cuts, diseased skin surfaces. For example, dettol, savlon, furacin, soframycin, etc. Disinfectants are the chemical substances which kill micro-organisms but they cannot be applied on living tissues. Examples : Phenol and chlorine.
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