The standard potential of `Ni^(2+), Ni` is `-0236 V`. It this electrode is coupled with a hydrogen electrode, the EMF of the cell becomes zero. Calculate the pH of acid used in electrode .

Answer

4

Explanation

`Ni_((s)) + 2H^(+) to Ni^(+2) + H_2 , E= E^(0) - (0.059)/(2) log([Ni^(+2)]PH_2)/([H^(+)]^(2))`
` 0.0236 - (0.059)/(2) log [H^(+)]^(2) , 0.059 pH = 0.236 , pH = 4 `