Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).

Updated on May 31, 2025 | By Learnzy Admin

Why copper is used to make hot water tanks and not steel:

Resistance to rust and corrosion:
Steel, which contains iron, easily reacts with water and oxygen to form rust (iron oxide). Rust weakens the steel, making it less durable and unsafe for storing water. Copper, on the other hand, is much more resistant to corrosion and does not rust easily. This means copper tanks last longer and stay safe for water storage.

Better heat conduction:
Copper is an excellent conductor of heat. This means it can quickly and evenly transfer heat to the water inside the tank. This helps in heating the water faster and saves energy. Steel is not as good a conductor, so it heats water more slowly.

Non-toxic and safe:
Copper does not release harmful substances into water, making it safe for storing hot water used for household purposes.

Maintenance and durability:
Because copper does not rust and conducts heat well, copper tanks require less maintenance and have a longer life compared to steel tanks, which may need frequent repairs due to rust.

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More Questions on Metals and Non-metals

  1. Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).
  2. A man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset but after a futile argument the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used?
  3. Differentiate between metal and non-metal on the basis of their chemical properties.
  4. You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.
  5. Give reasons (a) Platinum, gold and silver are used to make jewellery. (b) Sodium, potassium and lithium are stored under oil. (c) Aluminium is a highly reactive metal, yet it is used to make utensils for cooking. (d) Carbonate and sulphide ores are usually converted into oxides during the process of extraction.
  6. What type of oxides are formed when non-metals combine with oxygen?
  7. State two ways to prevent the rusting of iron.
  8. In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte?
  9. Name two metals which will displace hydrogen from dilute acids, and two metals which will not.
  10. What are amphoteric oxides? Give two examples of amphoteric oxides.
  11. You are given a hammer, a battery, a bulb, wires and a switch. (a) How could you use them to distinguish between samples of metals and non-metals? (b) Assess the usefulness of these tests in distinguishing between metals and non-metals.
  12. Food cans are coated with tin and not with zinc because (a) zinc is costlier than tin. (b) zinc has a higher melting point than tin. (c) zinc is more reactive than tin. (d) zinc is less reactive than tin.
  13. An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be (a) calcium (b) carbon (c) silicon (d) iron.
  14. Which of the following methods is suitable for preventing an iron frying pan from rusting? (a) Applying grease (b) Applying paint (c) Applying a coating of zinc (d) All of the above
  15. Which of the following pairs will give displacement reactions? (a) NaCl solution and copper metal (b) MgCl₂ solution and aluminium metal (c) FeSO₄ solution and silver metal (d) AgNO₃ solution and copper metal
  16. What are alloys?
  17. Which metals do not corrode easily?
  18. What chemical process is used for obtaining a metal from its oxide?
  19. Name two metals which are found in nature in the free state.
  20. Define the following terms. (i) Mineral (ii) Ore (iii) Gangue
  21. Why do ionic compounds have high melting points?
  22. Show the formation of Na₂O and MgO by the transfer of electrons.
  23. Write the electron-dot structures for sodium, oxygen and magnesium.
  24. What would you observe when zinc is added to a solution of iron(II) sulphate? Write the chemical reaction that takes place.
  25. Which gas is produced when dilute hydrochloric acid is added to a reactive metal? Write the chemical reaction when iron reacts with dilute H₂SO₄.
  26. Write equations for the reactions of (i) iron with steam (ii) calcium and potassium with water
  27. Why is sodium kept immersed in kerosene oil?
  28. Explain the meanings of malleable and ductile
  29. Give an example of a metal which (i) is a liquid at room temperature. (ii) can be easily cut with a knife. (iii) is the best conductor of heat. (iv) is a poor conductor of heat.