Question

In the following molecular orbital diagram of HCI: MO diagram for HCl molecule o'p2 H1s TInb Tb СІ Зр 3pz Onb CI 3s Which is the LUMO? Select one: a. 35 b. 3p 3s 15 here to search

Answer 1

LUMO (lowest unoccupied molecular orbital) is the lowest emptied or unoccupied molecular orbital of the given molecule. Filling of all valence electrons (one electron of H atom and seven electrons of Cl atom) are filled starting from the lowest energy sigma bonding molecular orbital. The next orbital in which the electron is to be filled after$\pi nb$ orbital is the $\sigma ^{*} 3p_{z}$ molecular orbital (this to be filled unoccupied orbital is termed as LUMO).

Thus from the given molecular orbital of the HCl molecule we can see that the $\sigma ^{*} 3p_{z}$ is the first unoccupied molecular orbital.

Hence the LUMO of HCl is $\sigma ^{*} 3p_{z}$ (option- 'g').