The spectrochemical series is
I⁻ < Br⁻ < Cl⁻ < F⁻ < OH⁻ < H₂O < NH₃ < en < NO₂– < CN⁻
Which of the following complexes will absorb visible radiation of the lowest energy (longest wavelength)?
a. [Cr(OH)₆]³⁻
b. [Cr(NH₃)₆]³⁺
c. [Cr(en)₃]³⁺
d. [Cr(H₂O)₆]³⁺
e. [Cr(F)₆]³⁻