Question

Compound that is both paramagnetic and coloured is

• A. $K_{2}Cr_{2}O_{7}$
• B. $\left( NH _{4}\right)_{2}\left[ TiCl _{6}\right]$
• C. $VOSO_{4}$
• D. $K_{3}\left[\right.Cu\left(\right. CN \left.\right)_{4}\left]\right.$

Answer 1

Answer: (C)

K₂Cr₂O₇ contains Cr⁺⁶(3d⁰) which is diamagnetic but coloured due to charge transfer spectra.
(NH₄)₂[TiCl₆] contains Ti⁴⁺(3d⁰), which is diamagnetic and colourless.
VOSO₄ contains V⁴⁺(3d¹), which is paramagnetic and coloured.
K₃[Cu(CN)₄] contains Cu⁺(3d¹⁰), which is diamagnetic and colourless.