Which one of the elements with the following outer orbital configurations may exhibit the largest number of…
Which one of the elements with the following outer orbital configurations may exhibit the largest number of oxidation states ?
$3 d^3, 4 \mathrm{~s}^2$
$3 d^5, 4 \mathrm{~s}^1$
$3 d^5, 4 s^2$
$3 d^2, 4 s^2$
Solution
Key Idea Number of oxidation states exhibited by d-block elements is the sum of number of electrons (unpaired) in d-orbitals and number of electrons in s-orbital.
(a) $3 \mathrm{~d}^3, 4 \mathrm{~s}^2 \Rightarrow \mathrm{O} . \mathrm{S}=3+2=5$
(b) $3 \mathrm{~d}^5, 4 \mathrm{~s}^1 \Rightarrow \mathrm{O} . \mathrm{S}=5+1=6$
(c) $3 \mathrm{~d}^5, 4 \mathrm{~s}^2 \Rightarrow \mathrm{O} . \mathrm{S}=5+2=7$
(d) $3 \mathrm{~d}^2, 4 \mathrm{~s}^2 \Rightarrow \mathrm{O} . \mathrm{S}=2+2=4$
Hence, element with $3 \mathrm{~d}^5, 4 \mathrm{~s}^2$ configuration exhibits largest number of oxidation states.