Chemistry - Coordination Chemistry Question with Solution | TestHub

Blue vitriol is ${\mathrm{CuSO}}_4\cdot 5{\mathrm{H}}_2\mathrm{O}$, better written $\left[\mathrm{Cu}{\left({\mathrm{H}}_2\mathrm{O}\right)}_4\right]{\mathrm{SO}}_4\cdot {\mathrm{H}}_2\mathrm{O}$.

(A) correct: ${\mathrm{Cu}}^{2+}$ is ${\mathrm{d}}^9$ with one unpaired electron - paramagnetic.

(D) correct: only four ${\mathrm{H}}_2\mathrm{O}$ molecules are directly coordinated to ${\mathrm{Cu}}^{2+}$; the fifth is hydrogen-bonded between sulphate and the coordination sphere.

(C) correct: ${\mathrm{Cu}}^{2+}$ here is $ds{p}^2$ hybridised, so a d orbital ($d_{x^2-y^2}$) is used in bond formation.

(B) incorrect: the covalent bonds (4 S-O bonds plus 10 O-H bonds in the water molecules) far outnumber the 4 coordinate bonds, so the ratio is not 1:4.

Correct statements: A, C, D