NTA Abhyas JEE Main2020ChemistryElectrochemistryPractice
The standard reduction potential for Cu 2 + /Cu is + 0.34 V . Calculate the reduction potential at pH = 14 for the above couple. K sp of Cu OH 2 = 1 × 10 − 19
Options
- A- 0.22 V
- B+ 0.22 V
- C- 0.44 V
- D+ 0.44 V
Correct answer
A. - 0.22 V
Step-by-step solution
When p H = 14, [ H + ] = 10 − 14 and [ O H − ] = 1 M K s p = [ C u 2 + ] [ O H − ] 2 = 10 − 19 ∴ [ C u 2 + ] = 10 − 19 [ O H − ] 2 = 10 − 19 The half cell reaction C u 2 + + 2 e − → C u E = E O − 0.059 2 log 1 [ C u 2 + ] = 0.34 − 0.059 2 log 1 10 − 19 = − 0.22 V