State and explain the pattern in the thermal stability of the Group 2 carbonates down the group.
The sulfates of Group 2 elements become less soluble down the group. Explain this trend.
Aluminium is obtained from $\text{Al}_2\text{O}_3$ by electrolysis. In this process, $\text{Al}_2\text{O}_3$ is dissolved in cryolite. The half-equation for the reaction at the anode is given as: $\text{O}^{2-} + \text{C} \rightarrow \text{CO} + 2e^-$. Use this half-equation to construct the ionic equation for the electrolysis of $\text{Al}_2\text{O}_3$.
Aluminium oxide is electrolysed for 3.0 hours with carbon electrodes and a current of $3.5 \times 10^5\,\text{A}$. Calculate the mass of aluminium formed.
Cryolite can be made from $\text{SiF}_4$. The first step in this conversion is the reaction of $\text{SiF}_4$ with $\text{H}_2\text{O}$, forming $\text{H}_2\text{SiF}_6$ and $\text{SiO}_2$. Write an equation for this reaction.