JEE Main 2019 — Coordination Compounds Question with Solution

NH₃ is a strong field ligand.

H₂O is weak field ligand.

Let $$\Delta$$_violet is the crystal field splitting energy of complex A and $$\Delta$$_yellow is for complex B.

$$\therefore$$   $$\Delta$$_yellow > $$\Delta$$_violet.

We know, $$\Delta$$ = $$\frac{hc}{{\lambda }_{absorb}}$$

Violet color will absorb yellow color and yellow color will absorb violet color.

$$\therefore$$   $$\Delta$$_yellow = $$\frac{hc}{{\lambda }_{violet}}$$

and $$\Delta$$_violet = $$\frac{hc}{{\lambda }_{yellow}}$$

So, $$\Delta$$_o of A is calculated from energy of yellow light and $$\Delta$$_o of B is calculated from energy of violet light.