WAEC Chemistry 2018 Paper

Concept:Copper is not reactive enough to release hydrogen from acids, while nitric acid oxidises the hydrogen formed.Explanation:Copper $(\mathrm{Cu})$ is placed below hydrogen in the reactivity series.Therefore, it cannot displace hydrogen $(\mathrm{H}^{+})$ from dilute acids.Nitric acid $(\mathrm{HNO}_{3})$ is a strong oxidising agent.Any hydrogen gas produced is immediately oxidised to water.Thus, $\mathrm{Cu}$ and $\mathrm{HNO}_{3}$ fail due to low reactivity and oxidising nature, respectively.Answer:A. reactivity and oxidation respectively.