A student carried out a titration to find the exact volume of dilute nitric acid needed to neutralise 20.0 cm3 of sodium hydroxide solution. Phenolphthalein indicator was used to identify the end point.
The student then mixed a fresh 20.0 cm3 sample of sodium hydroxide solution with the exact volume of nitric acid determined from the titration, but without adding any indicator. This new mixture was then heated to evaporate most of the water and left to crystallise.
Explain why this new mixture was evaporated to produce a pure sample of solid sodium nitrate, rather than the mixture remaining at the end of the titration.
Practise Edexcel GCSE Chemistry Acids with exam-style questions for Foundation and Higher tier. 276 questions, matched to the Edexcel GCSE Chemistry (1CH0) 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.
