Which of the following statement (s) is/are true for sodium…

Chemistry S and P - Block Elements (S - Block Elements Not In Syllabus ) Alkali Metals Single Correct MCQ

Published by: CGP EDU Academic Team

Published on: August 13, 2026

Which of the following statement (s) is/are true for sodium thiosulphate ?

It acts as an antichlor

It is used as an reducing agent in iodometric titration.

It reacts with hydrochloric acid to form SO2 and sulphur.

It is used in photography as hypo to dissolves excess of AgBr as soluble complex.

Text Solution

Verified by Experts

The correct answer is:

CHECK THE SOLUTION.

(a, b, c, d)

It removes the chlorine from the surface of fibres (while dyeing) according to following reaction.

Na2S2O3 + 4Cl2 + 5H2O 2NaHSO4 + 8HCl

Therefore , it is known as antichlor.

I3– + S2O32– 3I– + S4O62–

This reaction finds application in the iodometric and iodimetric methods of titrimetric analysis.

S2O32– + H+ S¯ (white) + SO2 + SO2 + H2O (disproportionation reaction).

2S2O32– + Ag+ [Ag(S2O3)2]3– (soluble complex) or [Ag(S2O3)3]5–

This reaction is utilized in photography where hypo is used as fixer.

Previous Question Next Question

Get practice questions, solutions, and test series in one place.

Share your experience with this question and solution.

Send your comment, doubt, correction, or feedback to admin.

What students say about this solution

No reviews yet. Be the first to write a review.