Question

Which compound is added to soap to impart antiseptic properties?
(a) Sodium lauryl sulphate
(b) Sodium dodecylbenzenesulfonate
(c) Rosin
(d) Bithionol

Answer 1

Hint: Soaps are combinations of fats, oils and salts, generally Sodium or Potassium salts of fatty acids, made by saponification method. To make soap antibacterial in nature, some disinfectants are added to them during preparation which imparts their antiseptic properties.

Complete step by step answer:
Soaps are of two types, non – antibacterial, and antibacterial. An antibacterial soap can remove $65\mathrm{\%}-85\mathrm{\%}$ of the bacteria from the human skin. Soaps are incorporated with germicidal (which kills germs) to impart their antiseptic properties. The antiseptic substance gives soap the ability to kill germs, and inhibit the growth of bacteria.
In option (a), Sodium lauryl sulphate, is a foaming agent, and it is used in soap to create lathe, and to give intense cleaning action.
In option (b), Sodium dodecylbenzene sulfonate is used in detergents to enhance their cleansing action.
In option (c), Rosin is an ingredient of soap which is used to make soaps hard or soft. It is also used in detergents to impart foaming ability.
In option (d), Bithionol is an inorganic salt. It has the properties of disinfectant. So, it is added to soap to impart antiseptic ability. Bithionol in soaps maintains the hygiene of the body by removing bad odours, preventing skin infections.

So, the correct answer is Option D .

Note:
According to a study of Scientific, and Innovative Research, Dettol brand soaps have the highest bacterial inhibition property. That means, they prevent the growth of bacteria better than other brands like Savlon, Lifebuoy Plus, Haldi Chandan, aloe vera, and neem.