Chemistry GCSE Science Worksheets, Questions and Revision

A student carries out a titration and records titres of 24.60, 23.85, 23.90 and 23.80 cubic centimetres. Calculate the mean titre that should be used.

1. Identify the rough titre: 24.60 is the first result and is well outside the others, so it is discarded as the rough run.
2. Check the remaining results for concordance: 23.85, 23.90 and 23.80 all lie within 0.10 cubic centimetres of each other, so all three are concordant.
3. Add the concordant titres: 23.85 + 23.90 + 23.80 = 71.55.
4. Divide by three: 71.55 / 3 = 23.85.
5. Final answer: mean titre = 23.85 cubic centimetres, using only the concordant results and stating that the rough titre was excluded.