JEE Main · 2019 · Shift-ImediumRDX-034

Given: Co3+ + e- Co2+; E = +1.81\ V Pb4+ + 2e- Pb2+; E = +1.67\ V Ce4+ + e- Ce3+; E = +1.61\ V Bi3+ + 3e- Bi; E =…

Redox Reactions · Class 11 · JEE Main Previous Year Question

Question

Given:

Co3++e−→Co2+;E∘=+1.81 V\mathrm{Co^{3+} + e^{-} \rightarrow Co^{2+}};\quad E^\circ = +1.81\ \mathrm{V} Pb4++2e−→Pb2+;E∘=+1.67 V\mathrm{Pb^{4+} + 2e^{-} \rightarrow Pb^{2+}};\quad E^\circ = +1.67\ \mathrm{V} Ce4++e−→Ce3+;E∘=+1.61 V\mathrm{Ce^{4+} + e^{-} \rightarrow Ce^{3+}};\quad E^\circ = +1.61\ \mathrm{V} Bi3++3e−→Bi;E∘=+0.20 V\mathrm{Bi^{3+} + 3e^{-} \rightarrow Bi};\quad E^\circ = +0.20\ \mathrm{V}

Oxidizing power of the species will increase in the order:

Options
  1. a

    Co3+<Ce4+<Bi3+<Pb4+\mathrm{Co^{3+} < Ce^{4+} < Bi^{3+} < Pb^{4+}}

  2. b

    Bi3+<Ce4+<Pb4+<Co3+\mathrm{Bi^{3+} < Ce^{4+} < Pb^{4+} < Co^{3+}}

    ✓
  3. c

    Co3+<Pb4+<Ce3+<Bi4+\mathrm{Co^{3+} < Pb^{4+} < Ce^{3+} < Bi^{4+}}

  4. d

    Ce4+<Pb4+<Bi3+<Co3+\mathrm{Ce^{4+} < Pb^{4+} < Bi^{3+} < Co^{3+}}

Correct Answerb

Bi3+<Ce4+<Pb4+<Co3+\mathrm{Bi^{3+} < Ce^{4+} < Pb^{4+} < Co^{3+}}

Detailed Solution

Principle: Higher E∘E^\circ (reduction potential) → stronger oxidising agent.

Step 1 — Arrange in increasing order of E∘E^\circ:

| Species | E∘E^\circ (V) | Oxidising power | |---|---|---| | Bi3+\mathrm{Bi^{3+}} | +0.20+0.20 | Weakest | | Ce4+\mathrm{Ce^{4+}} | +1.61+1.61 | ↑ | | Pb4+\mathrm{Pb^{4+}} | +1.67+1.67 | ↑ | | Co3+\mathrm{Co^{3+}} | +1.81+1.81 | Strongest |

Step 2 — Increasing order of oxidising power: Bi3+<Ce4+<Pb4+<Co3+\mathrm{Bi^{3+} < Ce^{4+} < Pb^{4+} < Co^{3+}}

Answer: Option (2)

Practice this question with progress tracking

Want timed practice with adaptive difficulty? Solve this question (and hundreds more from Redox Reactions) inside The Crucible, our adaptive practice platform.

Practice in The Crucible →Browse Redox Reactions chapter →

More JEE Main Redox Reactions PYQs

2025medium

Match the List-I with List-II | | List-I (Redox Reaction) | | List-II (Type) | |---|---|---|---| | A | CH4(g) + 2O2(g) - CO2(g) + 2H2O(l) | I | Disproportionation | | B | 2Na(s) -[] 2Na(s) + H2(g) |…

2024medium

Thiosulphate reacts differently with iodine and bromine in the reactions given below: 2S2O32- + I2 S4O62- + 2I- S2O32- + 5Br2 + 5H2O 2SO42- + 4Br- + 10H+ Which of the following statement justifies…

2024easy

Which of the following cannot function as an oxidising agent?

2023medium

Strong reducing and oxidizing agents among the following, respectively, are

2021easy

Identify the process in which change in the oxidation state is five:

View all 49 Redox Reactions PYQs →
Given: Co3+ + e- Co2+; E = +1.81\ V Pb4+ + 2e- Pb2+; E = +1.67\ V Ce4+ + e- Ce3+; E = +1.61\ V Bi3+… (JEE Main 2019) | Canvas Classes