Question

In dry Cell, Cathode is
A. $Zn$
B. $C$
C. $Zn + N{H_4}Cl$
D. $C + Mn{O_2}$

Answer 1

We know that a cathode is an electrode which absorbs electrons and anode is an electrode which discharges electrons. We also know that a dry cell is an electric battery. Dry cell is made up of an outer zinc container which acts as an anode.

Complete step by step answer:
We are given to determine what compound is used as a cathode in a dry cell.
Dry cell is a primary cell, which means it cannot be easily recharged after one use, it must be discarded after the charge in it is completed whereas a secondary cell can be recharged.
So most primary cells like dry cells use electrolytes that are present within absorbent materials.
Dry cell is also known as the Leclanche cell. In the Leclanche cell, zinc is used as an anode and carbon is used as a cathode. Carbon is used as a cathode because it can absorb electrons and it has less negative potential than zinc. The purpose of the carbon rod is to allow the flow of electrons. The central carbon rod is surrounded by a mixture of carbon and manganese(IV) dioxide ($Mn{O_2}$). The carbon powder will increase the electrical conductivity of $Mn{O_2}$ and retain the moisture of the electrolyte in the dry cell.
Zinc and its compounds therefore are not used as cathodes. Manganese dioxide ($Mn{O_2}$) acts as a depolarizer in the dry cell.
Hence, the option B is the correct answer.

Note: Cation is an ion formed after losing electrons but cathode absorbs electrons, in the same way anion is an ion formed after gaining electrons but anode loses electrons. Do not confuse between cation, anion with cathode, anode as they are completely opposite.