Looking for classes? Ksquare Career Institute, Bengaluru →
Four diatomic species are listed below. Identify the correct order in which the bond order is increasing in them:
A
$He_2^+ < O_2^- < NO < C_2^{2-}$
B
$NO < O_2^- < C_2^{2-} < He_2^+$
C
$O_2^- < NO < C_2^{2-} < He_2^+$
D
$C_2^{2-} < He_2^+ < O_2^- < NO$
Detailed Solution
Bond order $= \frac{1}{2}(N_b - N_a)$
$He_2^+$ (3 e⁻): $\frac{1}{2}(2 - 1) = 0.5$
$O_2^-$ (17 e⁻): $\frac{1}{2}(10 - 7) = 1.5$
NO (15 e⁻): $\frac{1}{2}(10 - 5) = 2.5$
$C_2^{2-}$ (14 e⁻): $\frac{1}{2}(10 - 4) = 3$
Increasing order: $He_2^+ < O_2^- < NO < C_2^{2-}$
$He_2^+$ (3 e⁻): $\frac{1}{2}(2 - 1) = 0.5$
$O_2^-$ (17 e⁻): $\frac{1}{2}(10 - 7) = 1.5$
NO (15 e⁻): $\frac{1}{2}(10 - 5) = 2.5$
$C_2^{2-}$ (14 e⁻): $\frac{1}{2}(10 - 4) = 3$
Increasing order: $He_2^+ < O_2^- < NO < C_2^{2-}$