Question

Match List I with List II

LIST I Coordination entity		LIST II Wavelength of light absorbed in nm
A	${\left[CoCl{\left(N{H}_3\right)}_5\right]}^{2+}$	I	310
B	${\left[Co{\left(N{H}_3\right)}_6\right]}^{3+}$	II	475
C	${\left[Co(CN{)}_6\right]}^{3-}$	III	535
D	${\left[Cu{\left(H_{2}O\right)}_4\right]}^{2+}$	IV	600

Choose the correct answer from the options given below:

• A. A-III, B-II, C-I, D-IV
• B. A-II, B-III, C-IV, D-I
• C. A-IV, B-I, C-III, D-II
• D. A-III, B-I, C-II, D-IV

Answer 1

Answer: (A)

LIST I Coordination entity		LIST II Wavelength of light absorbed in nm
A	${\left[CoCl{\left(N{H}_3\right)}_5\right]}^{2+}$	I	535
B	${\left[Co{\left(N{H}_3\right)}_6\right]}^{3+}$	II	475
C	${\left[Co(CN{)}_6\right]}^{3-}$	III	310
D	${\left[Cu{\left(H_{2}O\right)}_4\right]}^{2+}$	IV	600

$E=\frac{hc}{\lambda }\Rightarrow E\propto \frac{1}{\lambda }$
$\Rightarrow \Delta (CFSE)\propto \frac{1}{{\lambda }_{\text{absorb }}}\propto \text{ strength of ligand. }$