Question

Most commonly used bleaching agent is _____________
A) Alcohol
B) Carbon dioxide
C) Chlorine
D) Sodium chloride

Answer 1

Hint: The bleaching agent is used which helps in lightening or whitening the substrate by chemical reaction. The bleaching powder is also a bleaching agent which is known as calcium oxychloride which acts as a bleaching agent and oxidising agent in the presence of dilute acid which gives a nascent oxygen on reaction. The activation of bleach is known as pre hydrolysis.

Complete step-by-step answer:
Bleaching agents are those compounds which are used to remove the colour from the substances such as textile. The bleaching process includes the oxidation and reduction process which degrade the system of the colours. When both oxidation and reduction processes occur in the same chemical reaction it is known as redox reaction.

Chlorine acts as a bleaching agent because it tends to release bleaches and disinfectants which depends on the property of its strong reactivity of chlorine towards the organic compounds especially because of its oxidising property as it has strong affinity for electrons. Chlorine needs moisture to occur in its bleaching action. When chlorine reacts with water it forms an unstable compound called hypochlorous and hydrochloric acid. So the hypochlorous acid dissociates and forms nascent oxygen.

The reactions are the following.
$$\begin{gathered} C{l}_2+H_{2}O\to HCl+HClO \\ HOCl\to HCl+[O] \end{gathered}$$
So when the colourled material is reacted with nascent oxygen it forms a colourless material.

So the correct answer is option ‘C’.

Note: Chlorine has the atomic number of 17 and it contains 17 protons and 17 electrons. It is used as a disinfectant and to get rid of the smell of putrefaction. It helps in manufacturing of paper and paper products. It is also used to manufacture dyes and plastics.