Answer
a) $CN$
b) $N_2 ^{2-}$
Work Step by Step
a. CN or NO
In the molecular orbital model, the species that is more likely to gain an electron is the one with a higher electron affinity.
Between CN and NO, the species that is more likely to gain an electron is CN.
Explanation:
- The cyanide ion (CN-) has a higher electron affinity compared to the nitric oxide molecule (NO).
- The electron affinity of CN is higher because the carbon atom in CN can more effectively stabilize the additional electron, forming a closed-shell configuration (C≡N-).
- In contrast, the electron affinity of NO is lower because the nitrogen atom in NO cannot as effectively stabilize the additional electron, leading to a less stable configuration.
Therefore, the CN species is more likely to gain an electron compared to the NO species.
b. $O_{2}^{2+}$ or $N_{2}^{2+}$
In this case, the species that is more likely to gain an electron is $N_{2}^{2+}$.
Explanation:
- The dinitrogen dication ($N_{2}^{2+}$) has a higher electron affinity compared to the dioxygen dication ($O_{2}^{2+}$).
- The nitrogen molecule in $N_{2}^{2+}$ can more effectively stabilize the additional electron, forming a more stable configuration.
- In contrast, the oxygen molecule in $O_{2}^{2+}$ has a lower electron affinity and cannot as effectively stabilize the additional electron.
Therefore, the $N_{2}^{2+}$ species is more likely to gain an electron compared to the $O_{2}^{2+}$ species.
