A student added 0.048 g of magnesium ribbon to an excess of dilute hydrochloric acid and collected the hydrogen produced in a gas syringe.
Mg+2HCl→MgCl2+H2\text{Mg} + 2\text{HCl} \rightarrow \text{MgCl}_2 + \text{H}_2Mg+2HCl→MgCl2+H2
The relative atomic mass of magnesium is 24. The volume of one mole of any gas at room temperature and pressure (rtp) is 24 dm3.
Figure: The apparatus used to collect and measure the volume of hydrogen produced

Calculate the amount, in moles, of magnesium added.
Determine the volume, in cm3\text{cm}^3cm3, of hydrogen produced at rtp.
The student found that the volume of hydrogen collected was less than the calculated volume.
Suggest one reason why.
40 exam-style questions on AQA GCSE Chemistry 3.5 Use of amount of substance in relation to volumes of gases, covering 3.5.1 Volumes of gases. Each one has a worked solution and a mark scheme showing where the marks go.