JEE PYQ: S Block Elements Question 17
Question 17 - 2020 (04 Sep Shift 2)
An alkaline earth metal ‘M’ readily forms water soluble sulphate and water insoluble hydroxide. Its oxide MO is very stable to heat and does not have rock-salt structure. M is:
(a) Sr (b) Ca (c) Mg (d) Be
Show Answer
Answer: (d)
Solution
Solubility of $\text{BeSO}_4$ is highest among the given metal sulphates. Solubility order for hydroxide is $\text{Be(OH)}_2 < \text{Mg(OH)}_2 < \text{Ca(OH)}_2 < \text{Sr(OH)}_2 < \text{Ba(OH)}_2$. Thus $\text{BeSO}_4$ is soluble and $\text{Be(OH)}_2$ is insoluble. BeO does not form rock salt like structure; it adopts the hexagonal wurtzite structure.
BETA
