Question 1 What are good conductors of electricity? Give example?
Question 2 What are bad conductors of electricity? Give example?
Question 3 Do liquids conduct electricity?
Question 4 What are electrolytes?
Question 5 What are strong electrolytes. Give example?
Question 6 What are weak electrolyte. Give example?
Question 7 What is an electrode?
Question 8 Name two types of electrodes?
Question 9 What is the difference in conduction of a solid and liquid?
Question 10 What are conducting liquids?
Good Conductors of Electricity
The materials which allows electric current to pass through them easily are called good conductors of electricity.
Poor Conductors of Electricity
The material which do not allow electric current to pass through them easily are called poor conductor of electricity.
The metal such as copper and aluminium allow electricity to pass through them easily, so they are good conductors of electricity.
The material such as rubber, plastic, wood do not allow electric current to pass through them so they are poor conductors of electricity.
The liquid that conduct electricity are solutions of acid bases and salts in water.
For example : Solution of sulphuric acid, hydrochloric acid in water conduct electricity.
Vinegar contains acetic acid and lemon juice contain citric acid also conduct electricity. A solution of sodium hydroxide, potassium hydroxide or base in water conduct electricity.
Copper sulphate, common salt also conduct electricity.
There are differences in the conduction of electricity by solids and liquids.
(1) In solids, electricity is carried by electrons but in liquid, electricity is carried by ions (positively charged and negatively charged ions). In solid like copper metal, electricity is carried by electrons but in a liquid like copper sulphate solution, electricity is carried by copper ions and sulphate ion.
(2) When electricity is passed through a solid, then no chemical change take place but when electricity is passed through a liquid, then a chemical change take place.
For example: When electricity is passed through a copper wire, no chemical change take place in it but when electricity is passed through acidified water, then a chemical change take place in which water is decomposed into hydrogen and oxygen gas.
The liquids which conduct electricity are called conducting liquids.
The chemical changes which take place in conducting liquids on passing electric current through them are called chemical effects of electric current.
A liquid which can conduct electricity is called an electrolyte.
A conducting liquid is called electrolyte. Copper sulphate solution conducts electricity, therefore copper sulphate solution is an electrolyte. A conducting liquid or electrolyte contain ions that is positively charged and negatively charged ions.
The flow of these ions conduct electricity through the conducting liquid or electrolyte.
The solution of acids, bases and salts in water are electrolytes.
Electrolytes are of two types :
(1) Strong electrolytes
(2) Weak electrolyte
A strong electrolyte is a liquid or solution which conducts electricity very well because it contains a lot of ions in it.
For example : Sulphuric acid solution, hydrochloric acid solution, nitric acid solution, sodium hydroxide solution, potassium hydroxide solution, common salt solution, copper sulphate solution, silver nitrate solution etc.
A weak electrolyte is a liquid or solution which conduct electricity to a lesser extent because it contains less number of ions.
For Example: lemon juice, carbonic acid solution, ammonium chloride solution, tap water, rain water etc.
A solid electrical conductor through which an electric current enters or leaves something like a dry cell or an electrolytic cell, is called an electrode.
Electrodes are of two Types
The electrodes which is connected to the positive terminal of the battery gets positively charged. The positively charged electrode is called anode.
The electrode which is connected to the negative negative terminal of the battery gets negatively charged. The negatively charged electrode is called cathode.
An arrangement having two electrodes kept in a conducting liquid or electrolyte in a vessel is called an electrolytic cell.
For example: If we keep 2 carbon electrodes in a beaker containing acidified water, it will be an electrolytic cell. An electrolytic cell is used for carrying out chemical reactions by passing an electric current through the conducting liquid.
A battery is used to pass an electric current through the electrolyte taken in the electrolytic cell during the study of chemical effects of electric current.