Q: Why do scientists prefer to classify materials as good or poor conductors instead of conductors and insulators?
A: Most materials can conduct electricity under certain conditions, so a more nuanced classification is more accurate.
Q: What types of solutions typically conduct electricity?
A: Solutions of acids, bases, and salts are good conductors of electricity.
Q: How does electroplating protect iron from corrosion?
A: By coating iron with a less reactive metal like zinc, the underlying iron is protected from direct exposure to air and moisture that cause rusting.
Q: What happens to the electrodes during electroplating?
A: One electrode loses metal (dissolves into the solution), while the other electrode gains a coating of metal from the solution.
Q: Why are LEDs useful in electrical testing?
A: LEDs can glow even with weak electric currents, making them more sensitive than traditional bulbs for detecting electrical conductivity.
Q: How do the bubbles form during electrolysis of water?
A: Hydrogen bubbles form at the negative electrode, while oxygen bubbles form at the positive electrode.
Q: Why is chromium used in electroplating?
A: Chromium provides a shiny appearance, resists corrosion, and protects against scratches, while being more economical than making entire objects from chromium.
Q: What happens if you pass current through copper sulphate solution?
A: Copper gets deposited on the electrode connected to the negative terminal of the battery.
Q: Why is it important to clean electrodes before electroplating?
A: Cleaning ensures a better, more uniform metal coating and removes any impurities that might interfere with the process.
