12. Solving a chemistry problem

205. For a redox element of the Pt|A,B||C,D|Pt type, write the equation of the electrochemical reaction in the element, calculate the EMF of the element at the indicated activities ai (mol/l) of the reaction participants and the equilibrium constant of the reaction at T=293 K .
A - Sn⁴⁺, B - Sn²⁺, C - ClO₂¯, D - ClO¯; aA=0.02, aB=0.01, aC=0.08, aD=0.15
Standard potentials of electrochemical reactions:
Pt| Sn⁴, Sn²⁺ Sn⁴⁺ 2e ↔ Sn²⁺ φ⁰ = 0.05V
Pt| ClO₂¯, ClO¯,OH¯ ClO₂¯ H₂O 2e ↔ ClO¯ 2OH¯ φ ⁰ = 0.66V