Home
Class 12
CHEMISTRY
The emf of a cell corresponding to the r...

The emf of a cell corresponding to the reaction
`Zn +2H^(+)(aq) rarr Zn^(2+) (0.1M) +H_(2)(g) 1` atm is `0.28` volt at `25^(@)C`. Calculate the `pH` of the solution at the hydrogen electrode.
`E_(Zn^(2+)//Zn)^(@) =- 0.76` volt and `E_(H^(+)//H_(2))^(@) = 0`

Text Solution

Verified by Experts

`E_(cell)^(@) = 0.76` volt
Applying Nernst equation `E_(cell)^(@) =E_(cell)^(@) - (0.0591)/(2)log.([Zn^(2+)][H_(2)])/([H^(+)]^(2))`
`0.28 = 0.76 -(-0.0591)/(2) log. ((0.1)xx1)/([H^(+)]^(2))`
`log.(0.1)/([H^(+)]^(2)) = (2xx 0.48)/(0.0591)`
`log 0.1 - log [H^(+)]^(2) = 16.24` [since, `-log[H^(+)] = pH]`
`2pH = 16.24 - log 0.1`
`pH = (17.24)/(2) = 8.62`
Promotional Banner

Similar Questions

Explore conceptually related problems

Emf of a cell corresponding to the reaction:- Zn(s) +2H^(+) (aq) rarr Zn^(2+)(aq) [0.1M] +H_(2)(g) [1.0atm] is 0.49V at 25^(@)C, E_(Zn^(2+)//Zn)^(@) = - 0.76 V . The pH of solution in cathode chamber is.

EMF of the cell Zn ZnSO_(4)(a =0.2)||ZnSO_(4)(a_(2))|Zn is -0.0088V at 25^(@)C . Calculate the value of a_(2) .

The standard emf for the cell cell reaction Zn + Cu^(2+) rarr Zn^(2+) + Cu is 1.10 volt at 25^@ C . The emf for the cell reaction when 0.1 M Cu^(2+) and 0.1 M ZN^(2+) solutions are used at 25^@ =C is .

Calculate the equilibrium constant for the reaction at 298K. Zn(s) +Cu^(2+)(aq) hArr Zn^(2+)(aq) +Cu(s) Given, E_(Zn^(2+)//Zn)^(@) =- 0.76V and E_(Cu^(2+)//Cu)^(@) = +0.34 V

The emf of the cell involving the following reaction, 2Ag^(+) +H_(2) rarr 2Ag +2H^(+) is 0.80 volt. The standard oxidation potential of silver electrode is:-