The correct order of A, B, C, and D in terms of wave number of light absorbed is:

STUDY MATERIALS
COURSES
MORE
SUCCESS STORY
ADMISSION
STORE

Back

JEE ADVANCE

CLASS XI - XII
CRASH COURSE

CLASS XI - XII

CRASH COURSE

JEE MAIN

CLASS XI - XII
CRASH COURSE

CLASS XI - XII

CRASH COURSE

NEET

CLASS XI - XII
CRASH COURSE

CLASS XI - XII

CRASH COURSE

BITSAT

CLASS XI - XII

CLASS XI - XII

CBSE BOARD

CLASS IX

CLASS X

CLASS XI

CLASS XII

CLASS VI

CLASS VII

CLASS VIII

UP BOARD

CLASS IX
CLASS X
CLASS XI
CLASS XII

CLASS IX

CLASS X

CLASS XI

CLASS XII

CUET

CRASH COURSE

CRASH COURSE

Courses

CLASSROOM COURSES
ONLINE COURSES

ONLINE COURSES

More

Solution

Q.
Consider the following complexes: [2024]

A. ${[CoCl {({NH}_{3})}_{5}]}^{2 +}$

B. ${[Co {(CN)}_{6}]}^{3 -}$

C. ${[Co {({NH}_{3})}_{5} (H_{2} O)]}^{3 +}$

D. ${[Cu {(H_{2} O)}_{4}]}^{2 +}$

The correct order of A, B, C, and D in terms of wave number of light absorbed is:

1 A < C < B < D

2 C < D < A < B

3 D < A < C < B

4 B < C < A < D

Ans.
(3)

More is crystal field splitting energy, more is energy of photon $(\frac{h c}{λ})$ absorbed by the complex. More is energy of photon absorbed, more is wavenumber $(\frac{1}{λ})$ absorbed.
Tetrahedral splitting is less than octahedral splitting. Thus ${[Cu {(H_{2} O)}_{4}]}^{2 +}$ absorbs photon of least wavenumber.
Order of field strength of given ligands is: ${Cl}^{-} < H_{2} O < {NH}_{3} < {CN}^{- 1}$ . Strong field ligands cause more splitting, thus order of splitting and order of wavenumber absorbed is:
${[CoCl {({NH}_{3})}_{5}]}^{2 +} (A) < {[Co {({NH}_{3})}_{5} (H_{2} O)]}^{3 +} (C) < {[Co {(CN)}_{6}]}^{3 -} (B)$

Want Us to Email you About Special Offers & Updates?