Question

Identify the set of paramagnetic ions among the following:

• A. $V^{2+}, Co^{2+} , Ti^{4+}$
• B. $Ni^{2+}, Cu^{2+} , Zn^{2+}$
• C. $Ti^{3+}, Cu^{2+} , Mn^{3+}$
• D. $Sc^{3+}, Ti^{3+} , V^{3+}$

Answer 1

Answer: (C)

The ions which contain unpaired electrons exhibit paramagnetic behaviour.

The electronic configuration of the ions are given below:

$Ti ^{3+}=1 s ^{2} 2 s ^{2} 2 p ^{6} 3 s ^{2} 3 p ^{5}$

$Cu ^{2+}=1 s ^{2} 2 s ^{2} 2 p ^{6} 3 s ^{2} 3 p ^{5} 3 d ^{9}$

$Mn ^{3+}=1 s ^{2} 2 s ^{2} 2 p ^{6} 3 s ^{2} 3 p ^{5} 3 d ^{4}$

Thus, all of them have unpaired electrons. Hence, they will show paramagnetic behaviour.

In option (B) $V ^{3+}$ does not possess any unpaired electrons.

In option (C) $Zn ^{2+}$ does not possess any unpaired electrons.

Similarly, in option (D) $Zn ^{2+}$ does not possess any unpaired electrons.