Question

In the cell, Zn|\[{\rm{Z}}{{\rm{n}}^{{\rm{2 + }}}}\]||\[{\rm{C}}{{\rm{u}}^{{\rm{2 + }}}}\]|Cu, the negative terminal is:
A. Cu
B. \[{\rm{C}}{{\rm{u}}^{{\rm{2 + }}}}\]
C. Zn
D. \[{\rm{Z}}{{\rm{n}}^{{\rm{2 + }}}}\]

Answer 1

Hint: There are two electrodes namely cathode and anode that consist of an electrochemical cell. These electrodes are dipped in a solution called electrolytes and two half cells are formed. When these two half cells are combined, it leads to the formation of a cell.

Complete Step by Step Solution:
Let's discuss the rules of representation of cells.
1)In a galvanic cell representation, the anode, where oxidation occurs, is to be written on the left and the cathode is to be written on the right-hand side.
2) The representation of the anode is done by writing the solid phase of the metal and then the cation of the metal. And the representation of the cathode is done by first writing the cation and then the metal.
3) The separation of metal and the cation is done by using a vertical line.
4) The salt bridge that does the function of the separation of two half cells is represented by two vertical lines.

Here, the given electrochemical cell consists of electrodes of copper and zinc.
So, the oxidation reaction that occurs at anode is,
\[{\rm{Zn}} \to {\rm{Z}}{{\rm{n}}^{2 + }} + 2{e^ - }\]
And we know that anode is the negative electrode.

And the cathodic reaction is,
\[{\rm{C}}{{\rm{u}}^{{\rm{2 + }}}} + {\rm{2}}{{\rm{e}}^ - } \to {\rm{Cu}}\]

Therefore, the negative terminal in Zn|\[{\rm{Z}}{{\rm{n}}^{{\rm{2 + }}}}\]||\[{\rm{C}}{{\rm{u}}^{{\rm{2 + }}}}\]|Cu is Zinc (Zn).
Hence, option C is right.

Note: A process in which the passing of electricity occurs through the electrolyte and a chemical reaction occurs is termed electrolysis. And a device that generates electricity through the process of electrolysis is called a galvanic cell or electrochemical cell.