Question

In electroplating of iron with zinc, iron rod act as __________ and zinc plate act as __________
A. cathode, anode
B. anode, cathode
C. positively charged electrode, negatively charged electrode
D. Both acts as positively charged electrodes

Answer 1

Hint: In electroplating, there are two electrodes used. By the use of electrochemical theory, you need to analyse the cathode and anode in this particular question, where iron and zinc rod is used. Oxidation and reduction reaction has to be taken into consideration.

Complete step by step answer:
The cathode is the electrode which has to be coated. An anode is some other material. Both anode and cathode are dipped into a solution called the electrolyte, which is a salt of the coating material.
So, in the given question, the iron rod has been coated with the zinc so the iron rod will act as cathode and zinc as an anode. In this process, the electrolyte is some zinc base salt. When we apply the current, then the zinc at the anode starts to dissolve in the electrolyte solution and then it slowly gets deposited on the iron rod (acting as the cathode).
There are many advantages of electroplating, first most and the major advantage is that it prevents iron from rusting because the zinc is more reactive than iron. The corrosion of zinc is ten times slower than iron, so a very thin layer at the iron rod can prevent the iron from rusting for a long time.
At the cathode, there is always a reduction reaction taking place, and at the anode, there is always an oxidation reaction. Anode and cathode are dipped in a solution, which is called the electrolyte. And by applying direct current between the cathode and anode, the oxidation and reduction reaction happens.

So, the correct answer is “Option A”.

Note:
You may go wrong in this question if you don’t know the electrode potentials of the given metals because the electroplating is dependent on oxidation and reduction reaction and if you know the electrode potential of both the metal then you know which metal oxidises and which metal reduces.