Question

$T{i}^{2+}$ is purple while $T{i}^{4+}$ is colourless, because

• A. there is no crystal field effect in $T{i}^{4+}$
• B. $T{i}^{2+}$ has $3d^2$ configuration
• C. $T{i}^{4+}$ has $3d^2$ configuration
• D. $T{i}^{4+}$ is a very small cation when compared to $T{i}^{2+}$ and hence, does not absorb any radiation.

Answer 1

Answer: (B)

$Ti(22)\to 3d^{2}4s^2$

$T{i}^{2+}\to 3d^{2}4s^0(d-d$ transition is possible, so it is coloured)

$T{i}^{4+}\to 3d^{0}4s^0$ (no $d-d$ transition, colourless)