CHEMICAL EFFECTS OF ELECTRIC CURRENT
CHEMICAL EFFECTS OF ELECTRIC CURRENT
ELECTRIC CURRENT
The rate of flow of charges is known as electric current.
CLASSIFICATION OF MATERIALS BASED ON CONDUCTIVITY
Materials are classified into three based on their conductivity:- conductors, semiconductors and insulators
- Materials that allow current to pass through them are called conductors
- Materials that do not allow current to pass through them are called insulators
- Materials which have a conductivity between conductors and insulators are called semiconductors
CONDUCTIVITY OF LIQUID
The conductivity of a liquid is based on the presence of ions(charged particles) in it. (in other words conductivity of the liquid is a measure of ions that are free to move)
NOTES:- IONS are charged atoms. positively charged atoms are known as cations and negatively charged atoms are known as cations
DIAGRAMMATIC REPRESENTATION OF ELECTRIC CURRENT THROUGH LIQUID
The positive electrode is known as the anode and the negative electrode is known as the cathode. The liquid which conducts electricity is called an electrolyte(lemon juice is an electrolyte here)
A CHEMICAL EFFECT IS OBSERVED WHEN AN ELECTRIC CURRENT IS PASSED THROUGH A LIQUID
The chemical effect observed when an electric current is passed through a liquid are- Bubbles of gas on electrodes
- Deposit of metals on the electrode
- change of colour of the solution
NOTE:- - Distilled water is not a good conductor of electric current because it does not contain free ions
- The liquid contains acid, base or salt will conduct electricity because they contain free ions
The chemical effect observed when an electric current is passed through a liquid are
- Bubbles of gas on electrodes
- Deposit of metals on the electrode
- change of colour of the solution
NOTE:-
- Distilled water is not a good conductor of electric current because it does not contain free ions
- The liquid contains acid, base or salt will conduct electricity because they contain free ions
ELECTROLYSIS OF WATER
The chemical decomposition of constituents of water(hydrogen and oxygen) on the passage of electric current is called electrolysis of water
The chemical decomposition of constituents of water(hydrogen and oxygen) on the passage of electric current is called electrolysis of water
ELECTROPLATING
It is a process of depositing a thin layer of metal on any conducting substance with the help of an electric current called electroplating. The object to be plated is made as the cathode(electrode connected to the negative terminal of the battery) and the metal which has to be deposited is made as the anode(electrode connected to the positive terminal of the battery). The electrolyte is usually a salt solution of the metal to be coated
It is a process of depositing a thin layer of metal on any conducting substance with the help of an electric current called electroplating. The object to be plated is made as the cathode(electrode connected to the negative terminal of the battery) and the metal which has to be deposited is made as the anode(electrode connected to the positive terminal of the battery). The electrolyte is usually a salt solution of the metal to be coated
APPLICATION OF ELECTROPLATING
- Metals that rust are often coated with other metals to prevent rusting. eg:- galvanization is done for iron articles (coating of a layer of zinc over the iron)
- chromium plating is done for taps, vehicle spare parts etc to give a bright attractive appearance and resist scratch and wear
- gold and silver are plated over the cutlery and jewellery items
- Metals that rust are often coated with other metals to prevent rusting. eg:- galvanization is done for iron articles (coating of a layer of zinc over the iron)
- chromium plating is done for taps, vehicle spare parts etc to give a bright attractive appearance and resist scratch and wear
- gold and silver are plated over the cutlery and jewellery items
