Question

Of the following transition metals, the maximum numbers of oxidation states are exhibited by :

• A. Chromium (Z = 24)
• B. Manganese (Z = 25)
• C. Iron (Z = 26)
• D. Titanium (Z = 22)

Answer 1

The correct option is B Manganese (Z = 25)

Electronic configuration:
$Cr:\left[Ar\right]3d^{5}4s^1$
$Mn:\left[Ar\right]3d^{5}4s^2$
$Fe:\left[Ar\right]3d^{6}4s^2$
$Ti:\left[Ar\right]3d^{2}4s^2$
Manganese shows maximum number of oxidation states because it has 5 unpaired electrons in 3d and also contains 2 electrons in 4s-subshell.Hence, oxidation states shown by Mn are +2, +3, +4, +5, +6, +7.
Other metals show the following oxidation states
Cr = +2, +3, +4, +5, +6
Fe = +2, +3
Ti = +2, +3, +4