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 x₁$\mathbf{x}_1$, x₂$\mathbf{x}_2$ and x₃$\mathbf{x}_3$ S cm² mol⁻¹$\mathrm{S\ cm}^2\ \mathrm{mol}^{-1}$, respectively then the molar conductance for Mohr's salt solution at infinite dilution would be given by x₁ + x₂ + 2x₃$\mathbf{x}_1 + \mathbf{x}_2 + 2\mathbf{x}_3$. In the light of the given statements, choose the correct answer from the options given below:

Related Formula

where, W$W$ = mass deposited Z$Z$ = electrochemical equivalent I$I$ = current in amperes t$t$ = time in seconds M$M$ = molar mass n$n$ = n-factor (electrons exchanged) F$F$ = Faraday's constant (96500 C/mol$96500 \text{ C/mol}$)

Core Logic

The electrolysis of zinc sulphate (ZnSO₄$ZnSO_4$) involves the reduction of zinc ions at the cathode:

Here, the n-factor (n$n$) is 2.

Step 1: Calculation

Given values: I = 0.015 A$I = 0.015\text{ A}$ t = 15 minutes = 15 × 60 seconds = 900 s$t = 15\text{ minutes} = 15 \times 60\text{ seconds} = 900\text{ s}$ M = 65.4 g/mol$M = 65.4\text{ g/mol}$ F ≈ 96500 C$F \approx 96500\text{ C}$

Plugging the values into Faraday's First Law:

Rounding to two decimal places (or nearest integer depending on convention), we get 45.75 × 10⁻⁴ g$45.75 \times 10^{-4}\text{ g}$.

Chapter Mix

Class 12 Chemistry: Electrochemistry

Core Logic

The Standard Reduction Potential (E^°$E^\circ$) measures a species' tendency to undergo reduction (gain electrons). A higher, more positive E^°$E^\circ$ value means the species has a stronger tendency to be reduced, which in turn makes it a stronger oxidizing agent.

Comparing the given E^°$E^\circ$ values: BrO₄^-$\mathrm{BrO}_4^-$: 1.74V$1.74\mathrm{V}$ IO₄^-$\mathrm{IO}_4^-$: 1.65V$1.65\mathrm{V}$ ClO₄^-$\mathrm{ClO}_4^-$: 1.19V$1.19\mathrm{V}$

The order of oxidizing power follows the magnitude of the reduction potential: BrO₄^- > IO₄^- > ClO₄^-$\mathrm{BrO}_4^- > \mathrm{IO}_4^- > \mathrm{ClO}_4^-$

Pattern Recognition

Higher +ve Standard Reduction Potential (SRP) = Stronger Oxidising Agent.

Chapter Mix

Class 12 Chemistry: Electrochemistry Class 12 Chemistry: The p Block Elements

Core Logic

Mn, Ni, and Cd metals are predominantly used in battery industries.

• Mn is used in dry cells (Leclanche cell).
• Ni and Cd are used in Nickel-Cadmium (Ni-Cd) rechargeable batteries.

Chapter Mix

Class 12 Chemistry: Electrochemistry

Core Logic

Conductivity of an electrolytic cell is affected by the concentration of the electrolyte, the nature of the electrolyte, and the nature of the solvent. It does not depend on the nature of the electrode used.

Chapter Mix

Class 12 Chemistry: Electrochemistry

Core Logic

The reduction reaction for copper is:

This shows that 2 moles of electrons (2 Faraday) are required to deposit 1 mole (or 1 gram atom) of Cu.

Therefore, 1 Faraday of electricity will deposit:

Step 1: Finding x

Hence, x = 5$x = 5$.

Chapter Mix

Class 12 Chemistry: Electrochemistry