Question

When $O_2$ is adsorbed on a metallic surface, electron transfer occurs from the metal to $O_2$. The true statements regarding this adsorption is/are:

• A. $O_2$ is physisorbed
• B. heat is released
• C. occupancy of ${\pi }_{2p}^{\ast }$ of $O_2$ is increased
• D. bond length of $O_2$ is increased

Answer 1

Answer: (B), (C), (D)

The correct options are
B heat is released
C occupancy of ${\pi }_{2p}^{\ast }$ of $O_2$ is increased
D bond length of $O_2$ is increased

When $O_2$ is absorbed on a metallic surface, $e^{-}$transfer occurs from the metal to $O_2$.

Heat is released due to the $e^{-}$ transfer or formation of $O-M$ bond, $M-$ metal occupancy of ${\pi }_{2p}^{\ast }$ of $O_2$ is increased as from double bond it changes to single bond $O-O-M$.