Chemical changes in Current effects

• Metals such as copper and aluminium are good conductors of electricity
• Materials like rubber and plastics are bad conductors of electricity
• Some liquids are good conductors of electricity, while a few are bad conductors
• Water obtained from sources like pumps, wells, ponds, and taps contain dissolved salts and are good conductors of electricity
• Distilled water is free of salt and is a bad conductor of electricity
• Passage of current through chemical solutions causes chemical reactions to take place
• Chemical effects of electric current include:

  • Formation of gas bubbles at electrodes
  • Deposition of metals at electrodes
  • Changes in solution color
• Electrolysis is the process by which ionic substances are decomposed into simpler substances when an electric current is passed through them
• A conductor is any material that allows an electric current to pass through it, like metals such as copper
• Insulators, also known as bad conductors, do not allow the free flow of an electric current through them, like rubber and plastic
• An electric circuit is a closed-loop path through which a current flows
• When the circuit path is closed, the current flows through it; when there is a break in the path (switch is open), the circuit is open and not conducting
• A tester is used to check the presence of electric current in a circuit
• Liquids conduct electricity when salts are dissolved in them
• Most conducting liquids are solutions of acids, bases, or salts
• Acids, bases, and salts conduct electricity due to the presence of ions when dissolved in a solution
• Distilled water is a bad conductor of electricity due to the absence of dissolved salts and minerals
• Electrodes are conductors immersed in a solution with their ends connected to the terminals of a battery, forming an electrochemical cell
• There are usually two electrodes: cathode (ve) and anode (+ve)
• An electrolyte is a solution in which electrodes are submerged and dissociate on the passage of electric current
• Electroplating is the process of depositing a layer of metal on another material using electricity
• Example: Using Copper Sulphate solution as electrolyte and copper electrodes for electroplating
• Applications of electroplating include:

  • Coating zinc on iron to prevent corrosion
  • Coating silver and gold for jewelry
  • Coating tin onto iron for cans
  • Chromium coating for car parts and bath fittings for a shiny appearance