Question

Which of the following has the highest $O-O$ bond energy ?

• A. $O_2$
• B. $O_2^{2+}$
• C. $O_2^{-}$
• D. $O_2^{2-}$

Answer 1

Answer: (B)

$O_2^{2+}$

Bond order $\propto$ Bond Energy

	$O_2$	$O_2^{2+}$	$O_2^{-}$	$O_2^{2-}$
Bond Order	$=\frac{8-4}{2}$ $=2$	$=\frac{8-2}{2}$ $=3$	$=\frac{8-5}{2}$ $=1.5$	$=\frac{8-6}{2}$ $=1$

$O_2^{2+}$ has this Highest Bond Order and hence require the Highest Bond Energy.