chemical effects of electric current

• Materials that allow electric current to pass through them are good conductors of electricity
• Materials that do not allow electric current to pass through them easily are poor conductors of electricity
• Metals such as copper and aluminium conduct electricity, while materials such as rubber, plastic, and wood do not conduct electricity
• Liquids can also conduct electricity
• When testing liquids for conductivity, if the liquid allows electric current to pass, the circuit of the tester becomes complete and the bulb glows
• If the liquid does not allow electric current to pass, the circuit of the tester is not complete and the bulb does not glow
• Even if a liquid conducts electricity, the bulb may not glow if the current through the circuit is too weak
• Distilled water is a poor conductor of electricity because it is free of salts
• Most liquids that conduct electricity are solutions of acids, bases, and salts
• Common salt, when dissolved in distilled water, makes it a good conductor of electricity
• When dissolved in distilled water, substances like lemon juice, dilute hydrochloric acid, caustic soda, and potassium iodide make it conducting
• Fruits and vegetables can also conduct electricity
• The change observed in a solution when electrodes are immersed in it and a current is passed can be considered a chemical change
• When electrodes are immersed in water and a current is passed, bubbles of oxygen and hydrogen are produced
• Oxygen bubbles form on the electrode connected to the positive terminal of the battery and hydrogen bubbles form on the other electrode
• Passing an electric current through a conducting solution causes chemical reactions
• Chemical effects of electric current include bubbles of gas forming on electrodes, deposits of metal seen on electrodes, and changes of color of solutions
• The process of depositing a layer of any desired metal on another material by means of electricity is called electroplating
• In electroplating, a metal is deposited on another material by passing an electric current through a conducting solution
• Electroplating is widely used in industry to coat metal objects with a thin layer of a different metal, such as chromium plating on car parts, bath taps, and kitchen gas burners
• Chromium plating is done on objects to provide a shiny appearance, corrosion resistance, and scratch resistance
• In electroplating, the metal deposited on one electrode is drawn from the solution, while an equal amount of metal gets dissolved from the other electrode
• Copper sulphate dissociates into copper and sulphate when electric current is passed through the solution during electroplating
• Electroplating is used to create objects with the appearance of expensive metals like silver and gold on less expensive metals
• Iron is coated with zinc to protect it from corrosion and rusting
• Electroplating is a common application of the chemical effects of electric current