Which of the following complex will absorb maximum wavelength of light?

Question

Which of the following complex will absorb maximum wavelength of light? (A) [ Co ( NH 3)5( H 2 O )]3+ (B) [ CoCl ( NH 3)5]2+ (C) [ Co ( NH 3)6]3+ (D) [ Co ( CN )6]3-

Tardigrade Admin · Accepted Answer

CFSE propto strength of ligand propto1 / λ ∵ complex [ CoCl ( NH 3)5]2+ has minimum charge among all the complex so has lower CFSE so will absorb maximum wavelength of light.

Q. Which of the following complex will absorb maximum wavelength of light?

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

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

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

$[C o (CN)_{6}]^{3 -}$

CFSE $\propto$ strength of ligand $\propto 1/ λ$
$∵$ complex $[C o Cl (N H_{3})_{5}]^{2 +}$ has minimum charge among all the complex so has lower CFSE so will absorb maximum wavelength of light.

Q. Which of the following complex will absorb maximum wavelength of light?

[Co(NH3​)5​(H2​O)]3+

[CoCl(NH3​)5​]2+

[Co(NH3​)6​]3+

[Co(CN)6​]3−

CFSE ∝ strength of ligand ∝1/λ ∵ complex [CoCl(NH3​)5​]2+ has minimum charge among all the complex so has lower CFSE so will absorb maximum wavelength of light.

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

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

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

$[C o (CN)_{6}]^{3 -}$

CFSE $\propto$ strength of ligand $\propto 1/ λ$
$∵$ complex $[C o Cl (N H_{3})_{5}]^{2 +}$ has minimum charge among all the complex so has lower CFSE so will absorb maximum wavelength of light.