Question

Bleaching action of chlorine is due to:

A) reduction

B) oxidation

C) acidic effect

D) basic effect

Answer 1

Hint: Bleach is a name used for any chemical product which is used industrially and domestically to remove color from fabric or fiber, or to remove stain in process is called bleaching.

Complete step by step answer:

Bleaching whitens fabric by removing natural colors. Example tan of linen is carried out by bleaching. This is an oxidation process. When chlorine reacts with water, it produces nascent oxygen. This nascent oxygen combines with colored substances present in organic matter, and oxidizes it to colorless substances.

 $ C{l_2} + {H_2}O \to HCl + HClO $ 

 $ HClO \to HCl + [O] $ 

Colored substance $  + [O] \to  $  Colorless substance

 $ HCl \to  $  Hydrochloric acid

 $ HClO \to  $  Hypochlorous acid

Chlorine acts as an oxidizing agent only in presence of moisture. Chlorine is a strong oxidizing agent. Therefore, from the above explanation the correct option is (B) oxidation.

Nascent oxygen is atomic oxygen and represented in a square bracket like [O]. Due to formation of nascent oxygen, chlorine acts as a strong oxidizing agent.

Chlorine is a very useful chemical. It is commonly used as antiseptic and used to make drinking water safe. It is also used in production of paper products, plastics dyes, medicines, antiseptic, insecticides, etc.

Bleaching action of chlorine is permanent because it involves the oxidation process.

Sulphur dioxides also bleaches but its action is temporary because it involves a reduction process.  $ S{O_2} $  removes oxygen from colored substance and makes it colorless

 $ S{O_2} + 2{H_2}O \to {H_2}S{O_4} + 4[H] $ 

Color material  $  + [H] \to  $  colorless matter.

Hence the correct option is (A).

Note: Dry chlorine gas does not act as a bleaching agent because it does not produce nascent oxygen. It is a strong oxidizing agent. It has a strong tendency to rip the electrons out of color producing molecules and produce stable  $ C{l^ - }. $ Color producing molecules are the most vulnerable molecules to oxidation.