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NEET CHEMISTRYElectrochemistryMedium

Question

Consider the following relations for emf of an electrochemical cell: (a) emf of a cell = (Oxidation potential of the anode) – (Reduction potential of the cathode) (b) emf of a cell = (Oxidation potential of the anode) + (Reduction potential of the cathode) (c) emf of a cell = (Reduction potential of the anode) + (Reduction potential of the cathode) (d) emf of a cell = (Oxidation potential of the anode) – (Oxidation potential of the cathode)

Which of the following combinations correctly represents the relation for the emf of the cell?

A

(a) and (b)

B

(c) and (d)

C

(b) and (d)

D

(c) and (a)

Step-by-Step Solution

The emf of an electrochemical cell is the potential difference between the two electrodes. It can be expressed in different ways depending on whether standard oxidation or reduction potentials are used:

  1. In terms of both oxidation and reduction potentials: Ecell=Eoxidation(anode)+Ereduction(cathode)E_{cell} = E_{oxidation}(\text{anode}) + E_{reduction}(\text{cathode}). This matches statement (b).
  2. Since Ereduction=EoxidationE_{reduction} = - E_{oxidation}, we can substitute the reduction potential of the cathode to get: Ecell=Eoxidation(anode)Eoxidation(cathode)E_{cell} = E_{oxidation}(\text{anode}) - E_{oxidation}(\text{cathode}). This matches statement (d).
  3. Alternatively, in terms of reduction potentials only (IUPAC convention): Ecell=Ereduction(cathode)Ereduction(anode)E_{cell} = E_{reduction}(\text{cathode}) - E_{reduction}(\text{anode}).

Therefore, statements (b) and (d) correctly represent the relation for the emf of a cell.

Exam Context & Concepts Covered

This question aligns with the NEET CHEMISTRY syllabus, specifically targeting concepts from Electrochemistry. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

CHEMISTRYElectrochemistryconsiderfollowingrelationselectrochemicaloxidation

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