Question

${{\rm{Z}}{{\rm{n}}_{\left( {\rm{s}} \right)}}\mid {\rm{Z}}{{\rm{n}}^{{\rm{2 + }}}}_{\left( {{\rm{aq}}} \right)}\mid \mid {\rm{C}}{{\rm{u}}^{{\rm{2 + }}}}_{{\rm{(aq)}}}\mid {\rm{C}}{{\rm{u}}_{\left( {\rm{s}} \right)}}{\rm{:}}}\\
{\left( {{\rm{cathode}}} \right){\rm{\;\;\;\;\;\;\;\;}}\left( {{\rm{anode}}} \right)}$ is
A. Weston cell
B. Daniel cell
C. Calomel cell
D. Faraday cell
E. Standard cell

Answer 1

Hint: An electrochemical cell is a device that is operated to transform chemical energy into electrical energy or vice-versa. This chemical energy is generated from a redox reaction which represents reduction and oxidation reactions.

Complete Step by Step Solution:
A cell comprises a glass vessel that possesses an electrolyte in its aqueous or molten state.
Electrolyte contains two metal rods attached to a battery and are known as electrodes.
The electrodes linked to the positive and negative terminal of the battery are the anode and cathode respectively.

Oxidation is the loss of electrons and it ensues at the anode.
Reduction is the gain of electrons that occurs at the cathode.

There are two categories of electrochemical cells:
I) Galvanic or voltaic cells convert chemical energy into electrical energy.
II) Electrolytic cells convert electrical energy to chemical energy.
Galvanic cells are based on spontaneous redox reactions.

In the given cell representation, we see that Zn is undergoing oxidation by losing two electrons at the anode.
\[{\rm{C}}{{\rm{u}}^{{\rm{2 + }}}}\] is undergoing a reduction reaction by gaining electrons.

The two lines represent the salt bridge.
A salt bridge is used to set up a galvanic cell.
Daniel cell is a type of galvanic cell that only uses Zn and Cu as electrodes.
Both the electrodes are dipped in two separate beakers.
The zinc electrode is dipped in zinc sulphate solution and the copper electrode in copper sulphate.
So, the cell represents the Daniel cell.
So, option (B) is correct.

Note: For a galvanic cell, by convention, the electrode on which oxidation takes place is written on the left-hand side and the other electrode on which the reduction takes place is written on the right-hand side. Single vertical lines depict the phase barriers of the electrodes and the double line depicts the salt bridge.