Electrochemical cells, Electrochemical cells: Definition, construction, working and applications

Electrochemical cells, Electrochemical cells: Definition, construction, working and applications

Question: What are electrochemical cells? Write its different types.

Answer.

Electrochemical Cells

A device that can convert chemical energy into electrical energy , or uses electrical energy to drive the chemical reaction taking place in it is called electrochemical cell.

Therefore, electrochemical cells are of two types.

i. Electrochemical cells.

ii. Galvanic cells

Question: What are electrochemical cells? Write its different types.

Answer

Electrolytic cells

An electrochemical cells in which electrical energy is used to derive the a chemical reaction are called electrolytic cells.

Construction:

An electrolytic cell consists of following parts:

a. A vessel containing an electrolyte (MX)

b. Two innert electrodes

c. A battery

Working

When two electrodes are connected with battery, electrons flow from anode to cathode in outer circuit and the cations move towards cathode and anions towards anode in the solution as shown in figure. At anode, anions are oxidized by losing electrons while at cathode, cations are reduced by gaining the electrons.

At anode

At cathode

Applications of Electrolytic cells

Following are uses of electrolytic cells.

1. Down cells are used for preparation of sodium metal along with chlorine gas as by product.

2. Nelson’s cells are used for commercial preparation of sodium hydroxide along with chlorine and hydrogen gases as by products.

3. Electrolytic cells are used for the commercial preparation of calcium, magnesium and many other metals.

4. Electrolytic cells are used for commercial preparation of aluminum metal.

5. Electrolytic cells are also used for purification of copper metal.

6. Electrolytic cells are used for electroplating of tin, silver, nickel etc on steel.

7. Electrolytic cells are also used for prevention of corrosion by preparation of anodized aluminum

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