Q14 / 75 · JEE Main 2025 (7 Apr Shift 1) · Chemistry
Given below are two statements :
Statement I : Mohr's salt is composed of only three types of ions-ferrous, ammonium and sulphate.
Statement II : If the molar conductance at infinite dilution of ferrous, ammonium and sulphate ions are $\mathrm{x}_1, \mathrm{x}_2$ and $\mathrm{x}_3 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$, respectively then the molar conductance for Mohr's salt solution at infinite dilution would be given by $\mathrm{x}_1+\mathrm{x}_2+2 \mathrm{x}_3$
In the light of the given statements, choose the correct answer from the options given below :
Statement I : Mohr's salt is composed of only three types of ions-ferrous, ammonium and sulphate.
Statement II : If the molar conductance at infinite dilution of ferrous, ammonium and sulphate ions are $\mathrm{x}_1, \mathrm{x}_2$ and $\mathrm{x}_3 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$, respectively then the molar conductance for Mohr's salt solution at infinite dilution would be given by $\mathrm{x}_1+\mathrm{x}_2+2 \mathrm{x}_3$
In the light of the given statements, choose the correct answer from the options given below :
- ABoth statements I and Statement II are false
- BStatement I is false but Statement II is true
- Correct answerCStatement I is true but Statement II are false
- DBoth statements I and Statement II are true
Solution
Mohr's salt : $\mathrm{FeSO}_4 \cdot\left(\mathrm{NH}_4\right)_2 \mathrm{SO}_4 \cdot 6 \mathrm{H}_2 \mathrm{O}$
Using Kohlrousch law
$\lambda_{\mathrm{m}}^{\infty}(\text { Mohr's salt })=\mathrm{x}_1+2 \mathrm{x}_2+2 \mathrm{x}_3$
Using Kohlrousch law
$\lambda_{\mathrm{m}}^{\infty}(\text { Mohr's salt })=\mathrm{x}_1+2 \mathrm{x}_2+2 \mathrm{x}_3$
Hence, the correct answer is option: 'C'.