A student sets up the apparatus shown below to prepare and collect carbon dioxide gas from the reaction between calcium carbonate and dilute hydrochloric acid.

State the purpose of the delivery tube.
Practise Edexcel GCSE Chemistry Acids 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.