Question

How many out of the following has more paramagnetic character than $Ti ^{2+}$ ion?
$Sc ^{3+}, Cr ^{2+}, Co ^{2+}, Fe ^{2+}, Mn ^{2+}, Cu ^{2+}$

Answer 1

Paramagnetism arises due to the presence of unpaired electrons. As the number of unpaired electrons increases, the magnetic moment increases and hence the paramagnetic character also increases.
$Ti ^{2+} \Rightarrow 3 d ^{2} \Rightarrow 2$ unpaired $e ^{-}$
$Sc ^{3+} \Rightarrow 3 d ^{0} \Rightarrow 0$ unpaired $e ^{-}$
$Cr ^{2+} \Rightarrow 3 d ^{4} \Rightarrow 4$ unpaired $e ^{-}$
$Co ^{2+} \Rightarrow 3 d ^{7} \Rightarrow 3$ unpaired $e ^{-}$
$Fe ^{2+} \Rightarrow 3 d ^{6} \Rightarrow 4$ unpaired $e ^{-}$
$Mn ^{2+} \Rightarrow 3 d ^{5} \Rightarrow 5$ unpaired $e ^{-}$
$Cu ^{2+} \Rightarrow 3 d ^{9} \Rightarrow 1$ unpaired $e ^{-}$
$Cr ^{2+}, Co ^{2+}, Fe ^{2+}$ and $Mn ^{2+}$ have more paramagnetic character than $Ti ^{2+}$ ion.