standard electrode potential of cupper and zinc

Determination of the standard electrode potential of cupper and zinc

The standard electrode potential of cupper and zinc is a important experiment arround the world. This experiment is valuable for the general chemistry as well as the applied chemistry. Values for standard electrode potentials are most often tabulated at 25 °C and with reference to astandard hydrogen electrode (SHE).

Determination of the standard electrode potential of cupper and zinc:

To determine the standard electrode potential of cupper and zinc the standard calomel electrode (SCE) is connected with copper or zinc electrode and the emf of the cell is determined by means of a potentiometer, Thus-

Ecell = Ecathode(red) – Eanode(red)

The cell for zinc (Zn) can be represented as-

Zn/Zn2+ || Calomel (standard) 

Calomel (standard) || Cu2+/Cu

From the nurst equation –

E=E– (2.303RTloga)/nF

Apparatus as well as chemicals required:

  1. Potentiometer
  2. standard cell
  3. Galvanometer
  4. Standard Calomel electrode
  5. Znic electrode
  6. Cupper electrode
  7. 0.1M Sloution of ZnSO4 and CuSO4

Procedure:

  1. 0.0001M, 0.001M and 0.01M solution is prepaired.
  2. Then by the help of the calomel electrode and Potentiometer we determin the potential of the Zn electrode at each concentration.
  3. For cupper the above process should be repeat again.

Data of the Experiment:

emf of the ZnSO4 solution

Concentration of ZnSO4 emf
0.1 0.963
0.01 0.956
0.001 0.919
0.0001 0.833

emf for CuSO4 solution

Concentration of ZnSO4 emf
0.1 0.093
0.01 0.072
0.001 0.051
0.0001 0.043

Calculation: 

Ecell of Cu electrode

we will use the Nurst equation to determine the standard emf of the cuppor as well as zinc.

concentrarion emf mean activity co-efficient MCu2+. γ+ log(MCu2++)
0.0001 0.043 1.00 0.0001 -4
0.001 0.051 0.734 0.00734 -3.14
0.01 0.072 0.4 0.004 -2.397
0.1 0.083 0.161 0.0161 1.79

Ecell of Zn electrode

we will use the Nurst equation to determine the standard emf of the zinc as well as cupper.

concentrarion emf mean activity co-efficient MCu2+. γ+ log(MCu2++)
0.0001 0.963 1.00 0.0001 -4
0.001 0.956 0.734 0.00734 -3.14
0.01 0.919 0.4 0.004 -2.397
0.1 0.833 0.161 0.0161 1.79

Graphs

https://i0.wp.com/i.imgur.com/t9636Q1.png?resize=2479%2C3259&ssl=1standard electrode potential of cupper and zinc

Result:

From the above Experiment to determine the standard electrode potential of cupper as well as zinc we get the two graphs.

Now From the graphs,

“The standard electrode potential of cupper and zinc are 0.084 volt and 1.06 volt respectively.”

Click on the reaction to learn balancing redox reaction easily by ion electron method

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