In the following molecular/ions
$O_2^{+},O_2^{-},C_2^{-2},N_2^{-2},N_2^{-4}$
Which one is paramagnetic and has highest bond length?
 

Analysis of Molecular/Ionic Species

Given species: O₂⁺, O₂^-, C₂^2-, N₂^2-, N₂^4-

Paramagnetism Analysis

Paramagnetism arises from unpaired electrons in molecular orbitals.

• O₂ neutral molecule is paramagnetic with 2 unpaired electrons
• O₂⁺ has one less electron than O₂, still paramagnetic
• O₂^- has one more electron than O₂, typically paramagnetic
• C₂^2-, N₂^2-, and N₂^4- have all paired electrons (diamagnetic)

Bond Length Analysis

Bond Length is inversely related to bond order. Higher negative charge weakens bonds and increases bond length.

Final Answer:

• Paramagnetic species: O₂⁺ and O₂^-
• Species with highest bond length: N₂^4-

N₂^4- is highly reduced with the greatest negative charge, resulting in the weakest bond and longest bond length among all the given species.