Electrochemical numerical

 Define electrochemical cell.

 The standard electrode potential of Cu/Cu and Z/Zn electrodes are +0.34V and -0.76V respectively

I) Write the cell notation indicating anode and cathode

ii) write the cell reaction

iii) calculate the emf of the cell

iv) predict the feasibility of the reaction with reason.

    ⁠ ⁠☞ An electrochemical cell is a device that converts chemical energy into electrical energy or vice versa by a redox reaction occurring at the electrodes.

I) The cell notation for the electrochemical cell using Cu and Zn electrodes can be written as:

Zn(s) | Zn2+(aq) || Cu2+(aq) | Cu(s)

The anode is Zn(s) | Zn2+(aq), and the cathode is Cu2+(aq) | Cu(s).

ii) The cell reaction can be written as follows:

Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s)

iii) To calculate the emf of the cell, we use the equation:

emf = E(cathode) - E(anode)

where E(cathode) is the standard electrode potential of the cathode and E(anode) is the standard electrode potential of the anode.

emf = E(Cu2+/Cu) - E(Zn2+/Zn)

emf = (+0.34 V) - (-0.76 V)

emf = +1.10 V

Therefore, the emf of the cell is +1.10 V.

iv) The cell reaction is feasible because the emf is positive, indicating that the reaction is spontaneous in the forward direction. The negative electrode potential for zinc indicates that it is the anode and will undergo oxidation, while the positive electrode potential for copper indicates that it is the cathode and will undergo reduction. Therefore, the reaction proceeds spontaneously in the forward direction.

Q.Mention the important applications of istandard hydrogen electrode. The standard electrode potential for Fe*3/Fe2 and I2/I^-are + 0.77 V and +0.54 V respectively.

i. Draw the standard cell notation. 

ii. Identify the anode and cathode as the current drawn from it.

 iii. Write the cell reaction taking place at the electrodes

iv. Calculate standard cell potential

     ⁠☞The important applications of the standard hydrogen electrode (SHE) are:

•It serves as a reference electrode for measuring the electrode potential of other electrodes.

•It is used to determine the standard electrode potentials of other half-cells.

•It is used to measure the pH of a solution.

i. The standard cell notation for the cell with Fe3+/Fe2+ and I2/I- electrodes using the SHE as the reference electrode can be written as:

Pt(s) | H2(g) (1 atm) | H+(aq) || Fe3+(aq) | Fe2+(aq) | I2(s) | I-(aq)

ii. The anode is Fe2+(aq) | Fe3+(aq), and the cathode is I2(s) | I-(aq).

iii. The cell reaction can be written as follows:

Fe2+(aq) + 2H+(aq) → Fe3+(aq) + H2(g)

2I-(aq) → I2(s) + 2e-

iv. To calculate the standard cell potential, we use the equation:

E°cell = E°(cathode) - E°(anode)

where E°(cathode) is the standard electrode potential of the cathode and E°(anode) is the standard electrode potential of the anode.

E°cell = E°(I2/I-) - E°(Fe3+/Fe2+)

E°cell = (+0.54 V) - (+0.77 V)

E°cell = -0.23 V

Therefore, the standard cell potential is -0.23 V. This indicates that the cell reaction is not feasible under standard conditions.