Waec Model Questions Vol1 2022 Chemistry Question 1

A student is required to determine the relative atomic mass of magnesium by preparing magnesium oxide. The apparatus consists of a clean porcelain crucible with lid, a balance (to 0.01 g), a Bunsen burner and tongs. The procedure is: 1. Weigh the empty crucible (M₁). 2. Add a small piece of magnesium ribbon and weigh the crucible with magnesium (M₂). 3. Heat the crucible strongly until the magnesium has completely reacted with oxygen to form magnesium oxide. Allow to cool and weigh the crucible with the product (M₃). Given the following measurements: - Mass of empty crucible, M₁ = 45.00 g - Mass of crucible + magnesium, M₂ = 45.24 g - Mass of crucible + magnesium oxide, M₃ = 45.40 g (Atomic mass of oxygen = 16.0 g mol⁻¹) Answer the following: