Chemistry · Ionic Equilibrium

JEE Main 2025 — 28 January, Evening Shift — Question 30

Arrange the following in increasing order of solubility product : $\mathrm{Ca}(\mathrm{OH})_{2}, \mathrm{AgBr}, \mathrm{PbS}, \mathrm{HgS}$

Option A:
$\mathrm{PbS}<\mathrm{HgS}<\mathrm{Ca}(\mathrm{OH})_{2}<\mathrm{AgBr}$
Option B:
$\mathrm{HgS}<\mathrm{PbS}<\mathrm{AgBr}<\mathrm{Ca}(\mathrm{OH})_{2}$
Correct
Option C:
$\mathrm{Ca}(\mathrm{OH})_{2}<\mathrm{AgBr}<\mathrm{HgS}<\mathrm{PbS}$
Option D:
$\mathrm{HgS}<\mathrm{AgBr}<\mathrm{PbS}<\mathrm{Ca}(\mathrm{OH})_{2}$

Answer: B

Based on the Ksp values and salt analysis cation identification, we can say that order of Ksp value is:

$\mathrm{HgS}<\mathrm{PbS}<\mathrm{AgBr}<\mathrm{Ca}(\mathrm{OH})_{2}$

Ksp values

$\mathrm{HgS} \rightarrow 4 \times 10^{-53}$

$\mathrm{PbS} \rightarrow 8 \times 10^{-28}$

$\mathrm{AgBr} \rightarrow 5 \times 10^{-13}$

$\mathrm{Ca}(\mathrm{OH})_{2} \rightarrow 5.5 \times 10^{-6}$

Answer key and solution verified before publishing.

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Exam: JEE Main 2025
Paper: 28 January, Evening Shift
Subject: Chemistry
Chapter: Ionic Equilibrium
Topic: Sparingly Soluble Salts, Solubility Product & Precipitation Conditions