Question

In electroplating of silver, ${\text{AgN}}{{\text{O}}_{\text{3}}}$ solution is usually used as:
A. oxidant
B. reductant
C. electrode
D. electrolyte

Answer 1

Hint: Electroplating is a widely used application of electrolytic cells. It requires a conducting solution(electrolyte) to carry out the process of plating a metal onto another. The electrolyte is the substance which when dissolved in solvent separates into cations and anions and is distributed uniformly.

Complete step by step answer:
An electrolytic cell basically converts electrical energy into chemical energy. It mainly consists of two parts:
1.Two electrodes: Cathode (negative electrode) and Anode (positive electrode).
2.Electrolyte: It is a substance that conducts the electric current and as a result gets dissociated into ions that move towards the respective electrodes.
Electroplating is a process of creating a metal coating on another metal with the help of electric current. In the case of electroplating of silver, silver coating is done on the other inferior metal.
 In this process, the substance on which the silver coating is to be done is made as a cathode and the substance to be coated, that is, silver bar is made as an anode. What happens is, to transfer the electrons from one electrode to another we require a conducting solution which is referred to as an electrolyte and in this case, we require a solution of silver-based compound such as ${\text{AgN}}{{\text{O}}_{\text{3}}}$. We dip the two electrodes into the solution and connect them to a circuit as a result the silver becomes the positive electrode and the substance on which coating is done becomes a negative electrode. When the electric current moves through the circuit, the silver nitrate solution (electrolyte) splits into ions.
 Silver ions are attracted towards the negatively charged electrode and slowly deposit on it which produces a thin layer of silver on the substance. Meanwhile, the negative nitrate ions move towards positive electrodes releasing electrons that move through the battery towards the negative electrode.
That’s how electroplating of silver is done and how ${\text{AgN}}{{\text{O}}_{\text{3}}}$ acts as an “electrolyte”.

So, the correct answer is “Option D”.

Note:
Always the substance on which coating is done should on cathode and substance to be coated is made anode ${\text{AgN}}{{\text{O}}_{\text{3}}}$ is generally avoided taking as an electrolyte as the deposition of silver will be very fast and not smooth and uniform.