99 Percentile Qs Bank for JEE MainChemistryd and f Block Elements
The yellow colour of chromate ion and orange colour of dichromate ion is due to
Options
- A(d )-d transition only
- Bcharge transfer only
- Cboth (d-d ) transition and charge transfer
- D(s-d ) transitions only
Correct answer
B. charge transfer only
Step-by-step solution
In both of chromate ( ( CrO ₄²⁻ ) ) and dichromate ( ( Cr ₂ O ₇²⁻ ) ) ions, ( Cr ) is present in +6 oxidation state, i.e. (d^0 )-configuration. So, (d-d ) transition is absent in both of the ions. Their intense colour (yellow of ( CrO ₄²⁻ ) and orange of ( Cr ₂ O ₇²⁻ )) is the charge transfer (ligand ( ) metal) of oxygen get transfered into vacant (d )-orbital of ( Cr ) (VI).