Chemistry · Practical Inorganic chemistry (Qualitative Analysis)

JEE Main 2024 — 30 January, Shift 1 — Question 56

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

Statement-I: The gas liberated on warming a salt with dil H2SO4\mathrm{H}_{2} \mathrm{SO}_{4}, turns a piece of paper dipped in lead acetate into black, it is a confirmatory test for sulphide ion.

Statement-II: In statement-I the colour of paper turns black because of formation of lead sulphite.

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

  1. Option A:

    Both Statement-I and Statement-II are false

  2. Option B:

    Statement-I is false but Statement-II is true

  3. Option C:

    Statement-I is true but Statement-II is false

    Correct
  4. Option D:

    Both Statement-I and Statement-II are true.

Answer: C

Step-by-step solution

Statement I is true: When a sulphide salt is warmed with dilute H2SO4\mathrm{H_2SO_4}, hydrogen sulphide gas (H2S)(\mathrm{H_2S}) is liberated. This gas turns a lead acetate–dipped paper black, which is a confirmatory test for the sulphide ion.

Statement II is false: The black colour is not due to the formation of lead sulphite. It is formed due to lead sulphide (PbS)(\mathrm{PbS}) as shown by the reaction:

H2S+Pb(CH3COO)2→PbS (black)+2 CH3COOH\mathrm{H_2S + Pb(CH_3COO)_2 \rightarrow PbS\,(black) + 2\,CH_3COOH}

Thus, Statement I is true but Statement II is false →\rightarrow Option C.

Answer key and solution verified before publishing.

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Exam
JEE Main 2024
Subject
Chemistry
Chapter
Practical Inorganic chemistry (Qualitative Analysis)
Topic
Identification of Anions
Given below are two statements, one is labelled as Statement I and… | JEE Main 2024 PYQ with Solution · DhiX AI