An element of group 2 forms covalent oxide which is amphoteric in nature and dissolves in water to give an amphoteric hydroxide. Identify the element and write chemical reactions of the hydroxide of the element with an alkali and an acid.
The only element from Group 2 which forms a covalent oxide and is amphoteric in nature is Beryllium, Be. The covalent oxide is BeO which is amphoteric. When dissolved in water, it forms Be(OH)2. The reactions of Be(OH)2 with an acid and a base are as follows.
Be(OH)2 reacts with a base to forms beryllate ion.
Be(OH)2 + 2OH–→ [Be(OH)4]2–
Be(OH)2 reacts with an acid to form beryllate chloride.
Be(OH)2 + 2HCl + 2H2O → [Be(OH)4]Cl2