Ans : (a) Electrochemistry :
Electrochemistry is the branch of chemistry which deals with such chemical reactions involving the inter-conversion of electrical energy and chemical energy.
Example :
Batteries , cell , electroplating and electrolysis are just a few examples of the applications of electrochemistry.
Electrolytes :
Chemical compounds which conducts electricity in molten state or through their aqueous solution accompanying a chemical change are known as electrolytes.
Example :
HCl , NaOH , H2SO4 , KOH etc.
Non - Electrolytes :
Chemical compounds which do not conduct electricity in molten state or through their aqueous solutions are known as non - electrolytes.
Example :
Sugar , Petrol , Benzene etc.
Electrochemical cell (Galvanic / Voltaic Cell) : A Galvanic cell converts chemical energy into electrical energy. Here, the redox reaction is spontaneous and is responsible for the production of electrical energy.The two half-cells are set up in different containers, being connected through the salt bridge or porous partition.The electrons are supplied by the species getting oxidized. They move from anode to the cathode in the external circuit.
Electrolytic cell : An electrolytic cell converts electrical energy into chemical energy.The redox reaction is not spontaneous and electrical energy has to be supplied to initiate the reaction.Both the electrodes are placed in a same container in the solution of molten electrolyte.The external battery supplies the electrons. They enter through the cathode and come out through the anode.
Electrolysis :
Electrolysis is the process by which ionic substances are decomposed (broken down) into simpler substances when an electric current is passed through them.
Electrolysis involves the following two important processes :
1. Positively charged ions move to the negative electrode during electrolysis. They receive electrons and are reduced.
2. Negatively charged ions move to the positive electrode during electrolysis. They lose electrons and are oxidised.
Hydrolysis :
Hydrolysis is a reaction involving the breaking of a bond in a molecule using water. The reaction mainly occurs between an ion and water molecules and often changes the pH of a solution.
In chemistry, there are three main types of hydrolysis.
(a) Salt hydrolysis.
(b) Acid hydrolysis.
(c) Base hydrolysis.
Electroplating :
Electroplating is the application of a metal coating to a metallic or other conducting surface by an electrochemical process. Electrolysis is used to electroplate objects. This is useful for coating a cheaper metal with a more expensive one, such as copper or silver.
Electroplating Process :
The negative electrode should be the object that is to be electroplated.
The positive electrode should be the metal that you want to coat the object with.
The electrolyte should be a solution of the coating metal, such as its metal nitrate or sulfate.