Enter the burette readings in Table 2.1. Fill in Table 2.1 with the volume used in each titration.
Enter the burette readings for Titration 4 in Table 2.2. Work out the volume of vinegar B added in Titrations 3 and 4.
Calculate the mean volume of A and of B required to neutralise $25.0\,\text{cm}^3$ of $0.400\,\text{mol dm}^{-3}$ aqueous sodium hydroxide.
Suggest why the titrations using A and B are repeated.
The reaction between ethanoic acid and sodium hydroxide is shown. $\text{CH}_3\text{COOH} + \text{NaOH} \rightarrow \text{CH}_3\text{COONa} + \text{H}_2\text{O}$ The response to (b) gives the mean volume of B needed to neutralise $25.0\,\text{cm}^3$ of $0.400\,\text{mol dm}^{-3}$ aqueous sodium hydroxide. Calculate the concentration of ethanoic acid in B. Give your answer to an appropriate number of significant figures.
Use your answer to (d) to find the mass of ethanoic acid in $500\,\text{cm}^3$ of B. [$M_r$ ethanoic acid, $60$]
Use your answers to (b) and (e) to find the mass of ethanoic acid in $500\,\text{cm}^3$ of A.
Suggest why the conical flask is rinsed with distilled water rather than $0.400\,\text{mol dm}^{-3}$ aqueous sodium hydroxide between titrations.
Some vinegars are brown rather than colourless. Suggest why this titration method would not work well for determining the concentration of ethanoic acid in brown vinegar.