Given below are two statements, one is labelled as Statement I and the other is labelled as Statement II. Statement I: S 8 solid undergoes disproportionation reaction under alkaline conditions to form S 2- and S 2 O 3 2- . Statement II: ClO 4 - can undergo disproportionation reaction under acidic condition. In the light of the above statements, choose the most appropriate answer from the options given below :

Statement I is correct and statement Il is incorrect.

Both statement I and statement Il are correct.

Statement I is incorrect and statement Il is correct.

Both statements I and statements ll are incorrect.

Chemistry · p-Block Elements (Group 15-18)

JEE Main 2024 — 31 January, Shift 2 — Question 60

Given below are two statements, one is labelled as Statement I and the other is labelled as Statement II.

Statement I: $\mathrm{S}_{8}$ solid undergoes disproportionation reaction under alkaline conditions to form $\mathrm{S}^{2-}$ and $\mathrm{S}_{2} \mathrm{O}_{3}^{2-}$ .

Statement II: $\mathrm{ClO}_{4}^{-}$ can undergo disproportionation reaction under acidic condition.

In the light of the above statements, choose the most appropriate answer from the options given below :

Option A:
Both statement I and statement Il are correct.
Option B:
Statement I is correct and statement Il is incorrect.
Correct
Option C:
Statement I is incorrect and statement Il is correct.
Option D:
Both statements I and statements ll are incorrect.

Answer: B

Step-by-step solution

Statement I is Correct: Elemental sulphur ( $\mathrm{S_8}$ ) undergoes disproportionation in alkaline medium, where sulphur is simultaneously reduced to sulphide ( $\mathrm{S^{2-}}$ ) and oxidised to thiosulphate ( $\mathrm{S_2O_3^{2-}}$ ).

Chemical reaction:

\mathrm{S_8 + 12\,NaOH \rightarrow 2\,Na_2S + Na_2S_2O_3 + 6\,H_2O}

Statement II is Incorrect: In the perchlorate ion ( $\mathrm{ClO_4^-}$ ), chlorine is present in its highest oxidation state $(+7)$ and therefore cannot undergo disproportionation under acidic conditions.

Thus, Statement I is correct and Statement II is incorrect (Option B).

Answer key and solution verified before publishing.

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Exam: JEE Main 2024
Paper: 31 January, Shift 2
Subject: Chemistry
Chapter: p-Block Elements (Group 15-18)
Topic: Compounds of Sulphur - preparation and properties

Choose the correct statements from the following A. All group 16 elements form oxides of general formula EO 2 and EO 3 where E= S, Se, Te…

Answer: B

Step-by-step solution

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