Question

need exact answer not wide explanation, plzz help,
Both NO and NO2 have odd number of electrons. NO is colourless but NO2 is coloured .Why????

Answer 1

Why is nitrogen oxide colourless while nitrogen dioxide is brown in colour?

Answer by The Burman
CONFIDENCE VOTES 3.0K
It all depends on the frequencies of light the compounds reflect and absorb. The color you see is reflected light at a certain frequency(corresponding to a combination of certain colors in the electromagnetic spectrum), while the rest is absorbed.

For example, the Nitrogen Oxide molecule absorb light at a frequency out of the visible range, and reflect all colors we can see. That is why we see that Nitrogen gas is a white gas(if the gas if concentrated enough). As for nitrogen dioxide, the molecules absorb a certain color. All the other colors are reflected as a brown color.

Answer 2

Hey there!!!

In NO2 molecule, colour is explained based on the presence of unpaired electron, which can be excited easily by the adsorption of visible light.
In NO molecule, the odd electron is also involved in bonding between two bonded atoms,
the excitation of which can be possible only in ultraviolet region.
Thus NO is colourless.


Hope it helps!!!!