Question

standard electrode potential of redox couples A2+/A, B2+/B, C/C2+ and D2+/D are 0.3 volt , -0.5 volt, - 0.75 volt and 0.9 volt respectively. which of these is the best oxidising and reducing agent respectively

Answer 1

standard electrode potential of redox couples A²⁺/A , B²⁺/B, C/C²⁺ and D²⁺/D are 0.3 V, -0.5 V , -0.75 V and 0.9 V respectively.

To find out : The best oxidizing agent and best reducing agent.

solution : here A²⁺ + 2e¯ ⇒A , E₁ = 0.3 V

B²⁺ + 2e¯ ⇒B , E₂ = -0.5 V

C ⇒C²⁺ + 2e¯ , E₃ = -0.75 V

so, C²⁺ + 2e¯⇒C , E₃ = 0.75 V

and D²⁺ + 2e¯⇒D , E₄ = 0.9 V

concept : The higher electrode potential for an electrode, more will be its tendency to get reduced (i.e., greater tendency to accept electrons) and vice - versa.

it means, higher the positive value of electrode potential, higher will be strength of oxidising agent and lower will be strength of reducing agent.

here higher positive value of electrode potential is 0.9V (for D).

and higher negative value of electrode potential is -0.5 V ( for B).

so, B is the best reducing agent and D is the best oxidizing agent.

Answer 2

Explanation:

hope it helps

Refer the img attached

:-)