Explain what the term weak acid means.
State the mathematical link between $pK_a$ and the acid dissociation constant $K_a$.
Using acidity, explain why the $pK_a$ values differ between acid 1 and acid 2, acid 2 and acid 3, and acid 3 and acid 4.
Draw a fully labelled diagram of the apparatus required to measure the voltage of an electrochemical cell made up of the standard hydrogen electrode and the standard $\text{Cu}/\text{Cu}^{2+}$ electrode.
For the cell drawn in (c)(i), calculate the $E^{\circ}_{\text{cell}}$ and state which electrode is positive.
A monobasic acid, $D$, has $K_a = 1.23 \times 10^{-5}\,\text{mol dm}^{-3}$. Calculate the pH of a $0.100\,\text{mol dm}^{-3}$ solution of $D$.
An electrochemical cell like the one you drew in (c)(i) was assembled, but with a $0.100\,\text{mol dm}^{-3}$ solution of $D$ in the hydrogen electrode rather than the standard solution. Using the data and the Nernst equation, $E = E^{\circ} + 0.059\log[\text{H}^+(aq)]$, calculate the new $E_{\text{cell}}$ for this experiment.