Question

Which category of the synthetic detergents is used in the toothpaste?
A. Anionic
B. Cationic
C. Neutral
D. None of these

Answer 1

Hint: To answer this question you can think of sodium lauryl sulfate, which is a synthetic detergent used in the toothpaste. Now try to find out its nature by the constituents present in it.

Complete step by step answer:
Synthetic detergents are mainly classified into three categories:
(i) Anionic detergents (ii) Cationic detergents and (iii) Non-ionic detergents

Mainly anionic detergents such as sodium or ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, etc. are used in toothpaste to clean the teeth and to provide a foam that helps to carry away the debris. In anionic detergents, the anionic part of the molecule is involved in the cleansing action.
Further, we should also know that sodium lauryl sulfates have significant antibacterial properties and can penetrate as well as dissolve the plaque.

Here, we can see the structure of sodium lauryl sulfate -

Therefore, we can conclude that the correct answer to this question is option A.

Additional information:
We should also know about other detergents and their uses -
Cationic Detergents - These are quaternary ammonium salts of amines with acetates, chlorides or bromides as anions.
Cetyltrimethylammonium bromide is a popular cationic detergent and is used in hair conditioners.
Non-ionic Detergents - They do not contain any ions in their constitution. One such detergent is formed when stearic acid reacts with polyethylene glycol.
Liquid dishwashing detergents are of non-ionic types.

Note: We should know that these days the branching of the hydrocarbon chain is controlled and kept to the minimum. Unbranched chains can be biodegraded more easily and hence we can prevent pollution.