Question

Two complexes $\left[Cr\right(H_{2}O{)}_6]C{l}_3$ $\left(A\right)$ and
$\left[Cr\right(N{H}_3{)}_6]C{l}_3$ $\left(B\right)$ are violet and yellow coloured, respectively. The incorrect statement regarding them is:

• A. ${\Delta }_o$ value of (A) is less than that of (B).
• B. ${\Delta }_o$ value of (A) and (B) are calculated from the energies of violet and yellow light, respectively
• C. Both absorb energies corresponding to their complementary colors.
• D. Both are paramagnetic with three unpaired electrons.

Answer 1

The correct option is B ${\Delta }_o$ value of (A) and (B) are calculated from the energies of violet and yellow light, respectively

The ${\Delta }_o$ order will be compared by using spectrochemical series, and not by the energies of the violet & yellow light. So the value of ${\Delta }_o$ will be $\left[Cr\right(H_{2}O{)}_{6}C{l}_3]<[Cr\left(N{H}_3{)}_6\right]C{l}_3$