Hardness in Water (Leaving Cert Chemistry): Quizzes

$\text{Ca}^{2+}$ and $\text{Mg}^{2+}$ ions

Scum (greyish, insoluble precipitate)

$\text{Ca(HCO}_3)_2$ and $\text{Mg(HCO}_3)_2$

By boiling

$\text{CaSO}_4$ or $\text{MgSO}_4$

No, it requires ion exchange

Ion exchange

$\text{Na}^{+}$ or $\text{H}^{+}$ ions

$\text{CaCO}_3$, $\text{H}_2\text{O}$, and $\text{CO}_2$

$\text{Ca}^{2+}$ precipitates as $\text{CaCO}_3$

It forms scum, requiring more soap

Calcium carbonate

Distilled water