Question

Given below are two statements :

Statement I: The number of pairs, from the following, in which both the ions are coloured in aqueous solution is 3 .

$\left\lbrack {Sc}^{3 +},{Ti}^{3 +} \right\rbrack,\left\lbrack {Mn}^{2 +},{Cr}^{2 +} \right\rbrack,\left\lbrack {Cu}^{2 +},{Zn}^{2 +} \right\rbrack$ and $\left\lbrack {Ni}^{2 +},{Ti}^{4 +} \right\rbrack$

Statement II : ${Th}^{4 +}$ is the strongest reducing agent among ${Th}^{4 +},{Ce}^{4 +},{Gd}^{3 +}$ and ${Eu}^{2 +}$.

In the light of the above statements, choose the correct answer from the options given below