Question

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

Give reasons for the following:

To make hot water tanks, copper is used and not steel.

Answer 1

1. Copper is a good conductor of heat and does not react with hot water; by contrast, iron reacts with hot water.
2. Iron reacts with steam to corrode the tank, whereas copper does not react with either substance.
3. Steam affects iron, while temperature fluctuations do not affect copper.
4. When hot water produces steam, iron reacts with it in the following forms:
   \[\ce{\underset{Iron}{3Fe} + \underset{Water}{4H2O} -> \underset{Ferric oxide}{Fe3O4} + \underset{Hydrogen gas}{4H2\uparrow}}\]

Therefore, copper rather than steel is used to make hot water tanks.