Neco 2019 Chemistry Question 5

A student carries out the reaction between magnesium metal and hydrochloric acid as shown below: Mg (s) + 2 HCl (aq) \rightarrow MgCl_2 (aq) + H_2 (g) The student weighs 10.0 g of Mg and measures 20.0 g of 37% (w/w) HCl solution. The density of the HCl solution is 1.19 g cm\(^{-3}\). After the reaction, the volume of hydrogen gas collected over water at 25\(^\circ\)C and 750 mmHg is measured to be 0.55 L. (The vapour pressure of water at 25\(^\circ\)C is 23.8 mmHg.) Answer the following: a) Identify the limiting reagent and show all calculations used to reach the conclusion. b) Calculate the theoretical mass of hydrogen gas that should be produced. c) Using the experimental data, determine the percent yield of hydrogen and the mass of excess magnesium remaining unreacted.