A student synthesises a sample of acetylsalicylic acid (aspirin) in a school laboratory. The percentage yield of the purified product is found to be 68%.
Give two reasons why the percentage yield of a preparation such as this is less than 100%.
Practise Edexcel GCSE Chemistry Quantitative analysis with exam-style questions for Foundation and Higher tier. 100 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.