This PSEB 8th Class Science Notes Chapter 14 Chemical Effects of Electric Current will help you in revision during exams.
PSEB 8th Class Science Notes Chapter 14 Chemical Effects of Electric Current
→ Some materials that allow current to pass through them are called conductors and some that do not allow the current to pass through them are called insulators.
→ Some liquids that allow an electric current to pass through them, are called electrolytes.
→ An electric bulb glows, when an electric current passes through it.
→ LEDs are used, when the electric current is very small.
→ Pure air is an insulator.
→ Tap water, saltwater, sea or pond water all conduct electricity as they contain impurities and salt them.
→ Pure distilled water is a non-electrolyte.
→ Solutions of acids, bases, and salts are good electrolytes.
→ The passage of an electric current through a conducting solution causes chemical reactions.
→ Evolution of gas, change of color of the solution, and deposits of metal on electrodes are a few examples of chemical effects of electric current.
→ Fruits and vegetables can also conduct electricity.
→ Passing an electric current through acidulated water produces bubbles of oxygen and hydrogen on +ve and -ve terminals respectively.
→ Electroplating is an important application of the chemical effect of electric current.
→ Electroplating is the process of depositing a layer of any desired (superior) metal on another metallic object (of base metal) by means of electricity.
→ Electroplating is very useful to obtain shiny and rust-proof articles by covering cheap metals with desired coatings of costlier metals.
→ Conductors: Materials that allow current to pass through them, are called conductors.
→ Insulators: Materials that do not allow current to pass through them, are called insulators.
→ Electrolysis: It is the process by which a substance (electrolyte) is decomposed into its basic components by passing an electric current through it.
→ Anode: The electrode, which is connected to the positive end of the battery is called the anode.
→ Cathode: The electrode, which is connected to the negative end of the battery is called the cathode.
→ Electrolyte: A salt solution that conducts electricity through it.