Three complexes, [CoCl(NH3)5]2+ (I) , [Co(NH3)5H2O]3+ (II) and [Co(NH3)6]3+ (III) absorb light in the visible region. The correct order of the wavelength of light absorbed by them is :

Question

Three complexes, [CoCl(NH3)5]2+ (I) , [Co(NH3)5H2O]3+ (II) and [Co(NH3)6]3+ (III) absorb light in the visible region. The correct order of the wavelength of light absorbed by them is : (A) (III) > (I) > (II) (B) (I) > (II) > (III) (C) (II) > (I) > (III) (D) (III) > (II) > (I)

Tardigrade Admin · Accepted Answer

A complex having strong field ligand has tendency to absorb light of highest energy. Among the three complexes.

[C o (N H_{3})_{6}]^{+ 3}

will absorb radiation of highest energy and least wavelength.

[C o (N H_{3})_{5} H_{2} O]^{3 +}

has field weaker than the above compound and therefore absorb radiation of lesser energy and more wavelength.

[C o Cl (N H_{3})_{5}]^{2 +}

has the weakest field and therefore will absorb light of least energy and highest wavelength.
Strength of ligand

N H_{3} > H_{2} O > Cl

.

Q. Three complexes, [CoCl(NH3​)5​]2+(I) , [Co(NH3​)5​H2​O]3+(II) and [Co(NH3​)6​]3+(III) absorb light in the visible region. The correct order of the wavelength of light absorbed by them is :

(III) > (I) > (II)

(I) > (II) > (III)

(II) > (I) > (III)

(III) > (II) > (I)

Q. Three complexes,
$[C o Cl (N H_{3})_{5}]^{2 +} (I)$ ,
$[C o (N H_{3})_{5} H_{2} O]^{3 +} (II)$ and
$[C o (N H_{3})_{6}]^{3 +} (III)$
absorb light in the visible region. The correct order of the wavelength of light absorbed by them is :