question_answer 47)

  Amphoteric hydroxides react with both alkalies and acids. Which of the following group 2 metal hydroxides is soluble in sodium hydroxide? (a) \[Be{{(OH)}_{2}}\]                    (b) \[Mg{{(OH)}_{2}}\]                  (c) \[Ca{{(OH)}_{2}}\]                     (d) \[Ba{{(OH)}_{2}}\]

Answer:

  (a) \[Be{{(OH)}_{2}}\] is amphoteric in nature. It reacts both with acids and alkalies. \[Be{{(OH)}_{2}}+2NaOH\to N{{a}_{2}}Be{{O}_{2}}+2{{H}_{2}}O\] \[Be{{(OH)}_{2}}+{{H}_{2}}S{{O}_{4}}\to BeS{{O}_{4}}+2{{H}_{2}}O\]