If [ Cu ( H_2 O )_4]^2+ absorbs a light of wavelength 600 nm for d-d transition, then the value of octahedral crystal field splitting energy for [ Cu…

If $\displaystyle \left[\mathrm{Cu}\left(\mathrm{H}_2 \mathrm{O}\right)_4\right]^{2+}$ absorbs a light of wavelength $\displaystyle 600$ nm for d-d transition, then the value of octahedral crystal field splitting energy for $\displaystyle \left[\mathrm{Cu}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$ will be \_\_\_\_ $\displaystyle \times 10^{-21} \mathrm{~J}$. [Nearest integer] (Given : $\displaystyle \mathrm{h}=6.63 \times 10^{-34} \mathrm{Js}$ and $\displaystyle \mathrm{c}=3.08 \times 10^8 \mathrm{~ms}^{-1}$ )