16
Question Questions 16
Give reasons, why copper is used to make hot water tanks and not steel (an alloy of iron).
Copper being below hydrogen in the reactivity series does not react with cold water, hot water or steam. However, iron reacts with steam. If the hot water tanks are made of steel (an alloy of iron), then iron would react vigorously with the steam formed from hot water as shown in the reaction below:
3Fe (s) + 4H2O (g) ⟶ Fe3O4 (s) + 4H2 (g)
Thus, to prevent corrosion, copper is used to make hot water tanks and not steel.