The enthalpy change of solution, $\Delta H^{\circ}_{\text{sol}}$, of the Group 2 sulfates becomes more endothermic down the group. State and explain the pattern in the solubility of the Group 2 sulfates down the group.
Write the expression for $K_w$, the ionic product of water.
The numerical value of $K_w$ rises with increasing temperature. Place a tick in the appropriate column in each row to show the effect of increasing the temperature of water on the pH and on the ratio $[\text{H}^+] : [\text{OH}^-]$.
At $298\,\text{K}$, an aqueous solution of sodium hydroxide has pH $13.25$. Calculate the concentration of the sodium hydroxide solution.
Buffer solutions are used to control the pH of a solution so that it stays within a narrow range. Write two equations to describe how hydrogencarbonate ions, $\text{HCO}_3^-$, and carbonic acid, $\text{H}_2\text{CO}_3$, regulate the pH of blood.
The $K_a$ for ethanoic acid is $1.75 \times 10^{-5}\,\text{mol dm}^{-3}$ at $298\,\text{K}$. When ethanoic acid dissolves in water, an equilibrium mixture containing two acid-base pairs is established. Write an equation for this equilibrium. In the boxes, label each species as acidic or basic to show how it behaves in this equilibrium.
A buffer solution was made by adding $30.0\,\text{cm}^3$ of $0.25\,\text{mol dm}^{-3}$ ethanoic acid, in excess, to $20.0\,\text{cm}^3$ of $0.15\,\text{mol dm}^{-3}$ sodium hydroxide. Calculate the pH of the buffer solution produced at $298\,\text{K}$. Give your answer to one decimal place.
Titration curves for two different acid-base reactions, M and N, are shown. Use the titration curve for reaction M to deduce the volume of acid added at the end-point for this titration.
The table shows some acid-base indicators. Name a suitable indicator for each acid-base titration, M and N. Explain your answers.