Question

The coordination complex, $\left[Cu\right(O{H}_2{)}_6{]}^{2+}$ has one unpaired electron. Which of the following statements are true about the coordination complex, $\left[Cu\right(O{H}_2{)}_6{]}^{2+}$ ?
(1) The complex is octahedral.
(2) The complex is an outer orbital complex.
(3) The complex is $d^{2}d{p}^3$ hybridized.
(4) The complex is diamagnetic.
(5) The coordination number is $6$.

• A. $1,4$
• B. $1,2,5$
• C. $2,3,5$
• D. $2,3$

Answer 1

The correct option is B $1,2,5$

The oxidation state of $Cu$ in $\left[Cu\right(H_{2}O{)}_6{]}^{2+}$ ion is +2, and configuration $3d^9$ thus $C{u}^{2+}$ have 1 unpaired electrons in 3d orbitals. The presence of unpaired electrons makes a complex paramagnetic. The coordination number is $6$ since water ligand are coordinated.
Six vacant orbitals form $s{p}^3{d}^2$ hybridised octahedral outer orbitals complex. Thus statement 1,2,5 are correct.