Inorganic Chemistry> Bond angle order of no2, no2-, no2+,no3- ...

Bond angle order of no2, no2-, no2+,no3- in decreasing order

Zafar Imam Ansari , 6 Years ago

Grade 12th pass

3 Answers

Arun

Last Activity: 6 Years ago

NO2- 3- 2 2+

For NO2-, the molecule is bent but we have 1 lone pair on nitrogen. Lone pair electron repulsion is more than the bonding electrons so the bond angle will be less than 120o.
In NO3-, there is no lone pair of electrons, all are bonding pairs leading to an ideal bond angle of 120o.
In NO2, the one lone electron exerts a less repulsion than a lone pair of electrons, so two bonding oxygen atoms are able to spread out more leading to bond angle greater than the ideal of 120o.
In NO2+, there is no lone pair, only bond pairs so the molecule is linear leading to a bond angle of 180o.

Tony

Last Activity: 6 Years ago

An easy way to calculate bond order is:

Bond Order=Valancy of peripheral atom + (Charge on whole atom) / No. Of peripheral atoms.

Example :

For No2-, peripheral atom here is oxygen

Bond order = 2 + (-1)/2

=2 - 0.5 = 1.5

Kushagra Madhukar

Last Activity: 4 Years ago

Hello student

The pictorial representation of the species mentioned and their respective angle in ascending order is as shown.

Let’s analyse each specie individually

NO₂^- → In this the hybridisation of central N atom is sp², which accounts for 120^o bond angle, but since the repulsion given by the lone pair of electrons is greater than the bond pair electrons, the O-N-O bond angle decreases and attains a value lesser than 120^o

NO₃^- → In this the hybridisation of central N atom is sp² and also there is no lone pair and only bond pair of electrons(which also undergo resonance and equalises bond order), therefore the angle between O-N-O remains unchanged and is equal to 120^o

NO₂ → In NO₂, instead of having a lone pair of electrons it only has a single elecron in its lone pair, which gives lesser repulsion to the O-N-O bond, even lesser than the bond pair – bond pair repulsion, therefore the O-N-O bond readjusts and its angle increases and attains a value greater than 120^o

NO₂⁺ → In NO₂⁺, the central N atom is sp hybridised and there is no lone pair on N atom, thus the angle between O-N-O bond becomes 180^o

Therefore the order of angle is- NO₂^- ₃^- ₂ ₂⁺

Regards,

Kushagra