Neco 2022 Chemistry Question 5

A student carries out the reaction between aluminium metal and copper(II) sulfate solution as shown below: \[ \text{Al (s)} + CuSO_{4} (aq) \rightarrow Al_{2}(SO_{4})_{3} (aq) + Cu (s) \] The student weighs 4.50 g of aluminium and adds it to 150.0 mL of 0.250 mol dm\(^{-3}\) copper(II) sulfate solution. After the reaction is complete, the copper metal is filtered, dried and weighed. The mass of copper obtained is 3.12 g. Answer the following questions: (a) Write the balanced chemical equation for the reaction. (b) Determine which reactant is the limiting reagent and calculate the theoretical mass of copper that could be formed. (c) Calculate the percentage yield of copper obtained in the experiment. (d) Calculate the mass of the excess reagent that remains unreacted after the reaction is complete.