A student set up an apparatus to determine the percentage of oxygen in the atmosphere. They passed 120 cm3120\text{ cm}^3120 cm3 of air repeatedly over a heated sample of copper powder in a sealed tube connected to two gas syringes.
At the end of the experiment, after the apparatus had cooled to room temperature, the volume of gas in the syringes was 108 cm3108\text{ cm}^3108 cm3. Analysis of the remaining gas showed that it still contained some oxygen.
Suggest one reason why not all of the oxygen in the air sample reacted with the copper.
Practise Edexcel GCSE Chemistry Earth and atmospheric science with exam-style questions for Foundation and Higher tier. 62 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.
