The standard electrode potential (E°) for OCl - / Cl - and -(1/2) Cl 2 respectively are 0.94 V and -1.36 V. The E°value for OCl - / (1/2) Cl 2 will be

Question

The standard electrode potential (E°) for OCl - / Cl - and -(1/2) Cl 2 respectively are 0.94 V and -1.36 V. The E°value for OCl - / (1/2) Cl 2 will be (A) -0.42 V (B) -2.20 V (C) 0.52 V (D) 1.04 V

Tardigrade Admin · Accepted Answer

The given half cell reactions can be written as

(i)

OC l^{-} + H_{2} O + 2 e^{-} \to C l^{-} + 2 O H E_{1}^{\circ} = 0.94 V

(ii)

C l^{-} \to \frac{1}{2} C l_{2} + e^{-} E_{2}^{\circ} = - 1.36 V

(iii)

OC l^{-} + H_{2} O + e^{-} \to \frac{1}{2} C l_{2} + 2 O H; E_{3}^{\circ} = ?

Now consider free energies

(Δ G^{\circ} = - n E^{\circ} F)

Δ G_{3}^{\circ} = Δ G_{1}^{\circ} + Δ G_{2}^{\circ}

or

- 1 \times F \times E_{3}^{\circ} = - 2 \times F (0.94) - 1 \times F (- 1.36)

or

E_{3}^{\circ} = 2 \times 0.94 - 1.36 = 0.52 V

Q. The standard electrode potential (E∘) for OCl−/Cl− and −21​Cl2​ respectively are 0.94V and −1.36V. The E∘value for OCl−/21​Cl2​ will be

-0.42 V

-2.20 V

0.52 V

1.04 V

Q. The standard electrode potential $(E^{\circ})$ for $OC l^{-} / C l^{-}$ and $- \frac{1}{2} C l_{2}$ respectively are $0.94 V$ and $- 1.36 V$ . The $E^{\circ}$ value for $OC l^{-} / \frac{1}{2} C l_{2}$ will be