Using $$MO$$ theory, predict which of the following species has the shortest bond length?
A.
$$O_2^ + $$
B.
$$O_2^ - $$
C.
$$\,O_2^{2 - }$$
D.
$$O_2^{2 + }$$
Answer :
$$O_2^{2 + }$$
Solution :
Bond order $$ = \frac{{{\text{No}}{\text{. of bonding electrons}} - {\text{No}}{\text{. of antibonding electrons}}}}{2}$$
Bond order in $$O_2^ + = \frac{{10 - 5}}{2} = 2.5$$
Bond order in $$O_2^ - = \frac{{10 - 7}}{2} = 1.5$$
Bond order in $$O_2^{2 - } = \frac{{10 - 8}}{2} = 1\,$$
Bond order in $$\,O_2^{2 + } = \frac{{10 - 4}}{2} = 3$$
$${\text{Since Bond order }} \propto \frac{1}{{{\text{Bond}}\,\,{\text{length}}}}$$
∴ Bond length is shortest in $$O_2^{2 + }.$$
Releted MCQ Question on Inorganic Chemistry >> Chemical Bonding and Molecular Structure
Releted Question 1
The compound which contains both ionic and covalent bonds is