Question

Select the correct increasing order of $10Dq.$ value for chromium complexes:
(1) $\left[Cr\right(en{)}_3{]}^{3+}$ (2) $\left[Cr\right(ox{)}_3{]}^{3-}$ (3) $[Cr{F}_6{]}^{3-}$ (4) $\left[CR\right(H_{2}O{)}_6{]}^{3+}$.

• A. $4<3<1<2$
• B. $3<2<4<1$
• C. $4<3<2<1$
• D. $3<4<1<2$

Answer 1

The correct option is B $3<2<4<1$

The correct increasing order of 10 Dq. value for chromium complexes is $3<2<4<1$ or $[Cr{F}_6{]}^{3-}<[Cr(ox{)}_3{]}^{3-}<[Cr(H_{2}O{)}_6{]}^{3+}<[Cr(en{)}_3{]}^{3+}$.
This is based on the relative positions of the ligands in the spectrochemical series which is based on the field strength as measured by experimental methods.