Concept:The observed color of a transition metal complex is the complementary color of the light it absorbs. The complex absorbs certain wavelengths to excite an electron during a \(d-d\) transition, and transmits the rest.
Solution:- The \([Ti(H_2O)_6]^{3+}\) complex contains \(Ti^{3+}\), which is a \(3d^1\) system.
- When white light passes through it, the single \(d\)-electron absorbs strongly in the yellow-green region of the visible spectrum to jump to a higher energy \(d\)-orbital (\(d-d\) transition).
- Because the yellow-green light is absorbed, the remaining wavelengths of light—primarily red and blue light—are transmitted.
- The mixture of transmitted red and blue light makes the solution appear violet/purple to the human eye.
Why other options are incorrect:- If it transmitted yellow light, it would not appear violet.
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