What colour is the solution in the conical flask before $R$ is added, and what colour is it at the end-point?
Use the burette diagrams to fill in the table and find the average volume of $R$ that was used.
Calculate the number of moles of sodium hydroxide present in $25.0\text{ cm}^3$ of $S$.
Since $1$ mol of acid neutralises $1$ mol of sodium hydroxide, work out the number of moles of the organic acid in the average volume of $R$.
Calculate the number of moles of the acid in $1.00\text{ dm}^3$ of $R$.
Using your answer to (e) and the information that $R$ contains $8.00\text{ g dm}^{-3}$ of the acid, work out the relative molecular mass of the acid.
The organic acid has the formula $\text{C}_n\text{H}_{2n+1}\text{CO}_2\text{H}$. Using your answer to (f), work out the value of $n$ and hence the molecular formula and the name of the organic acid. [$A_r$: H, 1; C, 12; O, 16]