WAEC Chemistry 2019 Paper

Concept:The metal with the higher oxidation potential is more electropositive and displaces the metal with lower oxidation potential from its salt solution.Explanation:Oxidation potential of Mg is $+2.37$ V.Oxidation potential of Al is $+1.66$ V.Since $+2.37 > +1.66$, Mg is more electropositive than Al.So Mg loses electrons more readily and reduces $\mathrm{Al^{3+}}$ ions to Al metal.Therefore, Mg will replace Al from its solution.Answer:D. replace Al