Question

Lauryl Alcohol on treatment with ${H_2}S{O_4}$ followed by neutralization forms a product which is –
a.) Cationic detergent
b.) Anionic detergent
c.) Neutral detergent
d.) Anti- Depressant

Answer 1

Hint: Lauryl alcohol, when treated with ${H_2}S{O_4}$leads to the formation of Lauryl hydrogen sulphate which on neutralization leads to sodium lauryl sulphate.
We will first come to know about Lauryl alcohol and then we will learn about the reaction.

Complete step-by-step answer:
Lauryl alcohol which is also called as “Dodecanol”, is an organic compound which is obtained from palm kernel oil or coconut oil.
Chemical formula - ${C_{12}}{H_{26}}O$
Molar mass – 186.34
Properties of Lauryl alcohol-

It is a fatty acid
It is tasteless & colorless
It has a floral odour.

Uses –
It is used to make surfactants.
It is used as a flavoring agent in food and cosmetics.

Now, when Lauryl alcohol is treated with ${H_2}S{O_4}$ followed by neutralization –
(Lauryl alcohol) $C{H_3}{\left( {C{H_2}} \right)_{10}}C{H_2}OH\,\,\xrightarrow{{{H_2}S{O_4}}}\,$(Lauryl hydrogen sulphate)$C{H_3}{\left( {C{H_2}} \right)_{10}}C{H_2}OS{O_3}H$$\xrightarrow{{NaOH\left( {aq.} \right)}}\,$(Sodium lauryl sulphate) $C{H_3}{\left( {C{H_2}} \right)_{10}}C{H_2}OS{O_3}Na$

Simple reaction is shown below-
\[C{H_3}{\left( {C{H_2}} \right)_{10}}C{H_2}OH\xrightarrow{{{H_2}S{O_4}}}\,C{H_3}{\left( {C{H_2}} \right)_{10}}C{H_2}OS{O_3}H\,\xrightarrow{{NaOH\left[ {aq} \right]}}C{H_3}{\left( {C{H_2}} \right)_{10}}C{H_2}OS{O_3}Na\]

Sodium lauryl sulphate $\left( {C{H_3}{{\left( {C{H_2}} \right)}_{10}}C{H_2}OS{O_3}Na} \right)$is our product which is an Anionic detergent.
Hence, the solution is B. Anionic detergent. Because it is a synthetic detergent in which a lipophilic hydrocarbon group molecule is an anion.

Anionic detergents are the sodium salts of the long- chain sulfonated alcohol or hydrocarbons.
Sodium lauryl sulphate is found in many personal care products such as shampoos, soaps as it is a very effective foaming agent and inexpensive too.
Also used in many cosmetic products for their cleaning and emulsifying properties.

Detergents are the water-soluble compounds which combine with impurities to make them more soluble.

On the basis of electrical charge of the surfactants they are classified into
Anionic detergent
Cationic detergent
Non- Ionic detergent

Note - Anionic detergent is a synthetic detergent in which a lipophilic hydrocarbon group molecule is an anion. Sodium lauryl sulphate is an example which is used in many personal care and cosmetic products.
Also, it causes irritation to the skin.