Question

Antichlor is a compound
a. which absorbs chlorine
b. which removes excess of \[{\text{C}}{{\text{l}}_{\text{2}}}\]from a material
c. which liberates \[{\text{C}}{{\text{l}}_{\text{2}}}\] from bleaching powder
d. which acts as a catalyst in the manufacture of \[{\text{C}}{{\text{l}}_{\text{2}}}\]

Answer 1

Hint: We must remember that the antichlor is a substance used in the textile and paper industry for the cleaning process.

Complete step by step solution:-
An antichlor is a substance that can decompose residual chlorine from a material after chlorine-based bleaching is carried out. This helps to prevent further reaction of chlorine with the material and damage it.
The most commonly used antichlor is sodium thiosulfate \[N{a_2}{S_2}{O_3}\]. It neutralizes the excess chlorine left on the textile or paper pulp. Other examples of antichlor are sodium bisulphite \[NaHS{O_3}\], potassium bisulphite \[KHS{O_3}\], sodium metabisulphite \[N{a_2}{S_2}{O_5}\], and hydrogen peroxide ${H_2}{O_2}$.
Therefore, we can conclude the correct answer is Option B. which removes excess of \[{\text{C}}{{\text{l}}_{\text{2}}}\] from a material.

Note: In the textile industry, the antichlor is added at the end of the bleaching process. After treating the material with antichlor, it should be thoroughly rinsed in water in order to remove any by-products left behind.
If the antichlor is sodium thiosulfate, \[{\text{N}}{{\text{a}}_{\text{2}}}{{\text{S}}_{\text{2}}}{{\text{O}}_{{\text{3 ,}}}}\] let’s see how it decomposes or in short removes the chlorine from the material.
\[{\text{N}}{{\text{a}}_{\text{2}}}{{\text{S}}_{\text{2}}}{{\text{O}}_{\text{3}}}{\text{ + C}}{{\text{l}}_{\text{2}}}{\text{ + }}{{\text{H}}_{\text{2}}}{\text{O }} \to {\text{ S + 2HCl + N}}{{\text{a}}_{\text{2}}}{\text{SO}}\]
As you can see in the above equation, sodium thiosulfate reacts with chlorine and water to produce sulphur, hydrogen chloride and sodium sulphate.
By this process we can remove the chlorine from the material.
Therefore, antichlor has nothing to do with bleaching powder, it only decomposes \[{\text{C}}{{\text{l}}_{\text{2}}}\] molecule.