A student titrated 25.0 cm325.0\text{ cm}^325.0 cm3 portions of an ethanedioic acid (H2C2O4\text{H}_2\text{C}_2\text{O}_4H2C2O4) solution of unknown concentration with a 0.125 mol/dm30.125\text{ mol/dm}^30.125 mol/dm3 sodium hydroxide (NaOH\text{NaOH}NaOH) solution.
The student's results are shown in the table below:
| Titration | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|
| Volume of sodium hydroxide solution added (in cm3\text{cm}^3cm3) | 24.70 | 23.85 | 24.15 | 23.90 | 23.80 |
The equation for the reaction is: 2NaOH+H2C2O4→Na2C2O4+2H2O2\text{NaOH} + \text{H}_2\text{C}_2\text{O}_4 \rightarrow \text{Na}_2\text{C}_2\text{O}_4 + 2\text{H}_2\text{O}2NaOH+H2C2O4→Na2C2O4+2H2O
Calculate the concentration of the ethanedioic acid in mol/dm3\text{mol/dm}^3mol/dm3.
Use only the student's concordant results. Concordant results are those within 0.10 cm30.10\text{ cm}^30.10 cm3 of each other.
Practise AQA GCSE Chemistry Reactions of acids with exam-style questions for Foundation and Higher tier. 43 questions covering Reactions of acids with metals, Neutralisation of acids and salt production, Soluble salts, The pH scale and neutralisation, Titrations (chemistry only), and Strong and weak acids (HT only), matched to the AQA GCSE Chemistry (8462) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.