State the meaning of partition coefficient.
The partition coefficient, $K_{pc}$, for butanoic acid between ethoxyethane and water is $3.50$. A $2.00\,\text{g}$ sample of butanoic acid in $100\,\text{cm}^3$ ethoxyethane is mixed with water. The mixture is then left until the concentration of butanoic acid in both solvents no longer changes. The mass of butanoic acid now present in the ethoxyethane layer is $1.62\,\text{g}$. Calculate the volume of water used.
Define buffer solution.
Suggest one organic compound, and one inorganic compound, that can be added to two different samples of aqueous butanoic acid to make buffer solutions.
Give the expression for the solubility product, $K_{sp}$, of aluminium hydroxide.
Calculate the numerical value of the $K_{sp}$ of aluminium hydroxide, and include the units of $K_{sp}$ in your answer.