A d - block metal $$\mathrm{X}(\mathrm{Z}=26)$$ forms a compound $$[\mathrm{X}(\mathrm{CN})_2(\mathrm{CO})_4]^{+}$$. Calculate its spin magnetic moment value.
Which one of the following compounds shows Geometrical isomerism?
A sweet smelling organic compound $$[\mathrm{A}]\left(\mathrm{C}_9 \mathrm{H}_{10} \mathrm{O}_2\right)$$ undergoes acid hydrolysis to form an acid [B].
Compound [B] further reacts with Ammonia followed by heating to yield [C].
Compound $$[\mathrm{C}]$$ when reacted with $$\mathrm{Br}_2$$ in caustic potash gave compound $$[\mathrm{D}]\left(\mathrm{C}_6 \mathrm{H} 7 \mathrm{~N}\right)$$ which gives a white precipitate with aqueous $$\mathrm{Br}_2$$.
Identify compounds $$[\mathrm{A}]$$ & $$[\mathrm{D}]$$
Arrange the following ions in the increasing order of their $$\Delta H_{(\text {hydration})}$$ values.
$$\mathrm{Cr}^{2+}, \mathrm{Co}^{2+}, \mathrm{Mn}^{2+}, \mathrm{Ni}^{2+}$$