Home
Class 12
CHEMISTRY
Given E(Cr^(3+)//cr)^@ =- 0.72 V, E(Fe^(...

Given `E_(Cr^(3+)//cr)^@ =- 0.72 V, E_(Fe^(2+)//Fe)^@ =- 0.42 V`. The potential for the cell
`Cr | Cr^(3+) (0.1 M) || FE^(2+) (0.01 M) |` Fe is .

A

`0.26V`

B

`0.339V`

C

`-0.339V`

D

`-0.26V`

Text Solution

Verified by Experts

The correct Answer is:
A
Anode
`2Cr - 6e rarr 2Cr^(3+)`
Cathode `3Fe^(2+) +6e rarr 3Fe`
Net cell reaction
`2Cr +3Fe^(2+) rarr 2Cr^(3+) + 3Fe`
Applying Nernst equation
`E = E_(cell)^(@)-(0.059)/(6)log.([Cr^(3+)]^(2))/([Fe^(2+)]^(3))`
`= 0.30 - (0.059)/(6)log.((01)^(2))/((0.01)^(3))`
`= 0.3 - 0.01 xx log 10^(4)`
`= 0.3 - 0.04 = 0.26 V`
Promotional Banner

Similar Questions

Explore conceptually related problems

Given, {:(E_(Fe^(3+) //Fe)^o + 3e Cr E^o =- 0.036 V),(E_(Fe^(3+) //Fe)^o =- 0.439 V):} The value of standard electrode ptoential for the charge,

Consider the following E^o values : E^o _Fe^(3+)//FE^(2+)o = + 0.77 V E_(Sn^(2+)//Sn) =- 0.14 V Under standard conditions the potential for reaction Sn(s) +2Fe^(3+) (aq) rarr 2Fe^(2+) (sq) + Sn^(2+) (aq) is.

The EMF of the cell, Cr|Cr^(+3) (0.1M) ||Fe^(+2) (0.01M)|Fe (Given: E^(0) Cr^(+3)|Cr =- 0.75 V, E^(0) Fe^(+2)|Fe =- 0.45 V)

The % of Fe^(+2) in Fe_(0.93)O_(1.00) is .

Given, standard electrode potentials, {:(Fe^(3+)+3e^(-) rarr Fe,,,E^(@) = -0.036 " volt"),(Fe^(2+)+2e^(-)rarr Fe,,,E^(@) = - 0.440 " volt"):} The standard electrode potential E^(@) for Fe^(3+) + e^(-) rarr Fe^(2+) is :

A half cell is prepared by K_(2)Cr_(2)O_(7) in a buffer solution of pH =1 . Concentration of K_(2)Cr_(2)O_(7) is 1M . To 3 litre of this solution 570 gm of SnCI_(2) is added which is oxidised completely to SnCI_(4) . Given: E_(Cr_(2)O_(7)^(-2)//Cr^(+3).H^(+))^(@) = 1.33V, (2.303)/(F) RT = 0.06 , Atomic of mass Sn = 119, E_(Sn^(+4)//Sn^(+2))^(@) = 0.15 Half cell potential E_(Cr_(2)O_(7)^(-2)//Cr^(+3))^(@) after teh reaction of SnCI_(2) is:

A half cell is prepared by K_(2)Cr_(2)O_(7) in a buffer solution of pH =1 . Concentration of K_(2)Cr_(2)O_(7) is 1M . To 3 litre of this solution 570 gm of SnCI_(2) is added which is oxidised completely to SnCI_(4) . Given: E_(Cr_(2)O_(7)^(-2)//Cr^(+3).H^(+))^(@) = 1.33V, (2.303)/(F) RT = 0.06 , Atomic of mass Sn = 119, E_(Sn^(+4)//Sn^(+2))^(@) = 0.15 Emf of the cell Pt|underset((0.1M))(Sn^(+2)),underset((0.2M))(Sn^(+4)),underset((1M))(H^(+)):||:underset((0.2M))(Cr_(2)O_(7)^(2-)),underset((1M))(Cr^(+3)),underset((1M))(H^(+)):|:Pt