Question

There are some facts given for dry cell, which statements are true
i.It is also called as leclanche cell
ii.It is also called as Daniel cell
iii.Electrolyte is a moist paste of \[4N{H_4}Cl\] and \[2ZnC{l_2}\] in starch
iv.Cathodic reaction is
\[2Mn{O_2} + 2N{H_4}^ + + 2{e^ - } \to M{n_2}{O_3} + 2N{H_3} + {H_2}O\]
State the correct facts.

Answer 1

Hint: We have to know that a dry cell has the electrolyte immobilized as a paste, with only enough moisture in it to allow current to flow. Unlike a wet cell, a dry cell can operate in any orientation without spilling, as it contains no free liquid.

Complete answer:
We will look at all the given statements one by one to know whether it’s correct or not. Statement i says that dry cell is also known as leclanche cell. This statement is correct as the leclanche cell is the zinc-carbon based traditional dry cell. It immediately became a commercial success in large sizes because of its readily available low-cost constituent materials. Next, on moving to statement ii. This statement is not true as Daniel cell is not a dry cell. The Daniel cell is a type of electrochemical cell. Statement iii is correct as electrolyte used in dry cells is a moist paste of ammonium chloride and zinc chloride in starch. Now the last statement which tells us about the cathodic reaction, let’s look at the cathodic reaction:
At anode: \[Zn \to Z{n^{2 + }} + 2{e^ - }\]
At cathode: \[Mn{O_2} \to N{H_4}^ + + {e^ - }\] on further reaction it gets converted to \[MnO(OH) + {H^ + }\]
Thus we can conclude that statements i, iii and iv are correct about dry cells.

Note:
We have to know that a cell in which electrical energy is generated within the cell itself is called a primary cell. It can also be named as dry cell. An electrolyte is a substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water.