Question
Question: A metal M readily forms water soluble sulphate MSO4, water insoluble hydroxide M(OH)2 and oxide MO. ...
A metal M readily forms water soluble sulphate MSO4, water insoluble hydroxide M(OH)2 and oxide MO. The oxide and hydroxide are soluble in NaOH. The M is :
A
Be
B
Mg
C
Ca
D
Sr
Answer
Be
Explanation
Solution
For alkaline earth metals,
(1) solubility of sulphates decreases down the group.
(2) solubility of hydroxide increases down the group.
BeO and Be(OH)2 are amphoteric; so they are soluble in NaOH forming soluble [Be(OH)4]2–.
Hence metal M is Be