Explain why the solubility of the Group 2 hydroxides, $\text{M(OH)}_2$, rises down the group.
Suggest a reason for the general decrease in the solubility of the Group 2 carbonates, $\text{MCO}_3$, down the group.
When carbon dioxide is bubbled through a saturated solution of calcium hydroxide (limewater), a white precipitate of calcium carbonate forms. Use the data in the table to decide, for each of Mg, Sr and Ba, whether a saturated solution of its hydroxide could also be used to test for carbon dioxide. Justify your answer. No calculations are needed.
Calculate the value of the solubility product, $K_{sp}$, of magnesium hydroxide at $25\,^{\circ}\text{C}$.
State what would be observed if a few drops of a saturated solution of barium hydroxide are added to a saturated solution of barium carbonate. Explain your answer.
The equation for forming the gaseous hydroxide ion is given as $\tfrac{1}{2}\text{H}_2\text{(g)} + \tfrac{1}{2}\text{O}_2\text{(g)} + e^- \rightarrow \text{OH}^-\text{(g)}$, $\Delta H = \Delta H_f^\theta(\text{OH}^-\text{(g)})$. Use the data in the table and from the Data Booklet to calculate $\Delta H_f^\theta(\text{OH}^-\text{(g)})$. You may find it helpful to construct a Born-Haber cycle.