Home
Class 12
CHEMISTRY
In the button cells widely used in watch...

In the button cells widely used in watches and other devices, the following reaction takes place:
`Zn (s) + Ag_(2)O (s) + H_2O (l) to Zn^(2+) (aq) + 2Ag (s) + OH^(-)` (aq)
Determine `E^(@)` and `Delta_(r)G^(@)` for the reaction.

Text Solution

Verified by Experts

Electrode reactions taking place in the button cell are as under :
`Zn(s) to Zn^(2+)(aq) + 2e^(-)`
`2Ag^(+)(aq) + 2e^(-) to 2Ag(s)`
---------------------------------------------------------------------
`Zn(s) + 2Ag^(+)(aq) to Zn^(2+)(aq) + 2Ag(s)`
Thus, n=2
`E^(@)` for the reaction can be obtained as under:
`E_("cell")^(@) = (E_("cathode")^(@) - E_("anode")^(@))`
`=+0.80 V - (0.76 V) = + 1.56 V`
Use the following relation to calculate `Delta_(r)G^(@)`
`Delta_(r)G^(@) =-nE^(@) F`
`=-301.080 kJ mol^(-1)`
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • ELECTROCHEMISTRY

    U-LIKE SERIES|Exercise CASE BASED/SOURCE-BASED INTEGRATED QUESTIONS|15 Videos

  • ELECTROCHEMISTRY

    U-LIKE SERIES|Exercise CASE BASED/SOURCE-BASED INTEGRATED QUESTIONS (MULTIPLE CHOICE QUESTIONS )|20 Videos

  • ELECTROCHEMISTRY

    U-LIKE SERIES|Exercise SELF ASSESSMENT TEST (SECTION D)|1 Videos

  • COORDINATION COMPOUNDS

    U-LIKE SERIES|Exercise SELF ASSESSMENT TEST|7 Videos

  • EXAMINATION PAPER 2020

    U-LIKE SERIES|Exercise SECTION D|15 Videos

Similar Questions

Explore conceptually related problems

In the button cells widely used in watches and other devices the following reaction takes place: Zn(s) + Ag_(2)O(s) + H_(2)O (l) to Zn^(2+) (aq) + 2Ag(s) + 2OH^(-)(aq) Determine DeltaG^(@) and E^(@) for the reaction Zn(s) to Zn^(2+) + 2e^(-) , E^(@) = 0.76 V Ag_(2)O + H_(2)O + 2e^(-) to 2Ag + 2OH^(-) E^(@) = +0.34 V

What type of a battery is the lead storage battery 7 Write the anode and the cathode reactions and the overall reaction occurring in a lead storage battery when current is drawn from it. (b) In the button cell, widely used in watches, the following reaction takes place : Zn(s) + Ag_(2)O (s) + H_(2)O (l) to Zn^(2+)(aq) + 2Ag (s) + 2OH^(-) (aq) Determine E^(@) and DeltaG^(@) for the reaction. [Given: E_(Ag^(+)//Ag)^(@) =+0.80 V, E_(Zn^(2+)//Zn)^(@) =-0.76 V]

Knowledge Check

  • Consider Delta G^(@) for the following cell reaction : Zn (s) + Ag_(2)O(s)+H_(2)O(l) hArr Zn^(2+)(aq)+2Ag(s)+2OH^(-)(aq) E_(Ag^(+)//Ag)^(@) = +0.80 and E_(Zn^(2+)//Zn)^(@) = - 0.76 V

    A
    `-305 kJ//mol`
    B
    `-301 kJ//mol`
    C
    `+305kJ//mol`
    D
    `+301kJ//mol`

  • A buttonn cell used in watches function as following Zn(s) +Ag_(2)O(s) +H_(2)O(l) rarr 2Ag(s)+Zn^(2+)(aq)+2OG^(-)(aq), E^(@)=0.34 V the cell potential will be

    A
    1.10 V
    B
    0.42 V
    C
    0.84 V
    D
    1.34 v

    • Similar Questions

    Explore conceptually related problems

    In the button cells widely used in watCHMes and other devices the following reaction takes place : Zn(s)+Ag_(2)O(s)+H_(2)O(l) rarr Zn^(2+)(aq)+2Ag(s)+2OH^(c-)(aq) Determine Delta_(r)G^(c-) and E^(c-) for the reaction.

    In the button cell, widely used in watches, the following reaction takes place Zn(s)+Ag_(2)O(s)+H_(2)O to Zn^(2+)(aq)+2Ag(s)+2OH^(-)(aq) Determine E^(@) and DeltaG^(@) for the reaction. (Given : E_(Ag^(+)//Ag)^(@)=+0.80 V,E_(Zn^(2+)//Zn)^(@)=-0.76 V

    (a) What type of a battery is the lead storage battery ? Write the anode and the cathode reactions and the overall occuring in a lead storage battery when current is drawn from it. (b) In the buttom cell, widely used in watches the following reaction take place Zn_((s)) + Ag_(2)O_((l)) rarr Zn^(2+)(aq) + 2Ag_((s)) + 2OH_((aq))^(-) . Determine E^(@) and DeltaG^(@) for the reaction. (given : E_(Ag^(+)//Ag)^(@) = +0.80 V , E_(Zn^(2+)//Zn)^(@) = - 0.76 V)

    Calculat the equilibrium constant for the reaction, Zn(s)+Ag_(2)O(s)+H_(2)O(l) rarr 2Ag(s)+Zn^(2+)(aq.)+2 OH^(-) (aq.) when E_(cell)^(@)=1.11 at 298 K.

    Write Nernst equation for the following cell reaction : Zn(s) | Zn^(2+)(aq)|| Cu^(2+)(aq) | Cu(s)

    Calculate Delta_(r)G^(@) and e.m.f. (E) that can be obtained from the following cell under the standard conditions at 25^(@)C: Zn(s)|Zn^(2+)(aq)" "Sn^(2+)(aq)|Sn(s) Given E_(Zn^(2+)//Zn)^(@)=-0.76V,E_(Sn^(2+)//Sn)^(@)=-0.14V And F=96500C" "mol^(-1) OR (a) Define conductivity and molar conductivity for the solution of an electrolyte. Discuss their variation with concentration. (b) Calculation the standard cell potential of the galvanic cell in which the following reaction takes place: Fe^(2+)(aq)+Ag^(+)(aq)toFe^(3+)(aq)+Ag(s) Calculate the Delta_(r)G^(@) and equilibrium constant of the reaction also. (E_(Ag^(+)//Ag)^(@)=0.80,E_(Fe^(3+)//Fe^(2+))^(@)=0.77V)

    Home
    Profile