A student carries out a titration using a standard solution of potassium hydroxide to find the concentration of a sample of nitric acid.
The table shows their results:
| Trial 1 | Trial 2 | Trial 3 | Trial 4 | Trial 5 | |
|---|---|---|---|---|---|
| Burette reading after adding the acid (cm3\text{cm}^3cm3) | 25.60 | 25.25 | 25.35 | 25.75 | 25.15 |
| Burette reading before adding the acid (cm3\text{cm}^3cm3) | 0.65 | 1.15 | 0.80 | 1.45 | 0.95 |
| Volume of acid added (cm3\text{cm}^3cm3) | 24.95 | 24.10 | 24.55 | 24.30 | 24.20 |
Concordant results are defined as those that differ by 0.20 cm3 or less.
Identify which trials are concordant.
Use the concordant results to calculate the average (mean) volume of acid added.
39 exam-style questions on Edexcel IGCSE Chemistry Acids, alkalis and titrations. Each one has a worked solution and a mark scheme showing where the marks go.