question_answer

Which of the following ions gives coloured solution?

A)  \[C{{u}^{+}}\]                                  

B)  \[Z{{n}^{2+}}\]

C)  \[A{{g}^{+}}\]                                  

D)  \[F{{e}^{2+}}\]

Correct Answer: D

Solution :

The ion which contains unpaired electrons  gives coloured solution. Among the given only\[F{{e}^{2+}}\]contains 4 unpaired electrons as \[_{26}Fe=1{{s}^{2}},2{{s}^{2}}2{{p}^{6}},3{{s}^{2}}3{{p}^{6}}3{{d}^{6}},4{{s}^{2}}\] \[_{26}F{{e}^{2+}}=1{{s}^{2}},2{{s}^{2}}2{{p}^{6}},3{{s}^{2}}3{{p}^{6}}3{{d}^{6}},4{{s}^{0}}\]                 Hence, it gives coloured solution.