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QJEEM14Chd529: JEE Main 2014 Chemistry - Class 12 JEEM14Chd529 Solution: The octahedral complex of a metal ion M 3+ with four…

The octahedral complex of a metal ion M3+ with four monodentate ligands L1, L2, L3 and L4 absorb wavelengths in the region of red, green, yellow and blue, respectively. The increasing order of ligand strength of the four ligands is :

Multiple Choice Options

  • A L3 < L2 < L4 < L1
  • B L1 < L2 < L4 < L3
  • C L4 < L3 < L2 < L1
  • D L1 < L3 < L2 < L4

Step-by-Step Verified Solution

JEE Main 2014 (Offline) Chemistry - Coordination Compounds Question 261 English Explanation

For a given metal ion, weak filed ligands create a complex with smaller Δ\Delta , which will absorbs light of longer λ\lambda and thus lower frequency. Conservely, stronger filled ligands create a larger Δ,\Delta , absorb light of shorter λ\lambda and thus higher v.i.e.v.i.e. higher energy.

\mathop {{\mathop{\rm Re}\nolimits} d}\limits_{\lambda = 650\,nm} \,\,\mathop { &lt; Yellow}\limits_{570\,\,nm} \,\,\mathop { &lt; Green}\limits_{490\,nm} &lt; \mathop {Blue}\limits_{450\,nm}

So order of ligand strength is

{L_1} &lt; {L_3} &lt; {L_2} &lt; {L_4}

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