JEE PYQ: S Block Elements Question 20
Question 20 - 2020 (08 Jan Shift 2)
A metal (A) on heating in nitrogen gas gives compound B. B on treatment with $\text{H}_2\text{O}$ gives a colourless gas which when passed through $\text{CuSO}_4$ solution gives a dark blue-violet coloured solution. A and B respectively, are:
(a) Na and $\text{NaNO}_3$ (b) Na and $\text{Na}_3\text{N}$ (c) Mg and $\text{Mg}_3\text{N}_2$ (d) Mg and $\text{Mg(NO}_3)_2$
Show Answer
Answer: (c)
Solution
$3\text{Mg} + \text{N}_2 \rightarrow \text{Mg}_3\text{N}_2$ (compound B). $\text{Mg}_3\text{N}_2 + \text{H}_2\text{O} \rightarrow 3\text{Mg(OH)}_2 + 2\text{NH}_3$. $4\text{NH}_3 + \text{CuSO}_4 \rightarrow [\text{Cu(NH}_3)_4]\text{SO}_4$ (dark blue coloured).
BETA
