Give reason- Dry cells are used widely in spite of their short life.
Answers
Answer:
Line art drawing of a dry cell: 1. brass cap, 2. plastic seal, 3. expansion space, 4. porous cardboard, 5. zinc can, 6. carbon rod, 7. chemical mixture.
A standard dry cell comprises a zinc anode, usually in the form of a cylindrical pot, with a carbon cathode in the form of a central rod. The electrolyte is ammonium chloride in the form of a paste next to the zinc anode. The remaining space between the electrolyte and carbon cathode is taken up by a second paste consisting of ammonium chloride and manganese dioxide, the latter acting as a depolarizer. In some designs, the ammonium chloride is replaced by zinc chloride.
Anode: Zn⟶Zn+2e
−
Cathode: 2NH
4
+
+2e
−
⟶2NH
3
+H
2
So at anode, oxidation of Zn takes place (zinc cup is used up and reduction of acidic 2NH
4
+
takes place.
Explanation: