chemistry question I can't answer would like help with

Question

2. (a) Draw at least two plausible resonance contributors for the nitrite ion (NO2-).

 

2. (b) Assign formal charges to each atom in the resonance structures of the nitrite ion (NO2-).

 

2. (c) How many double bonds are present in the experimental (true) structure of the nitrite ion (NO2-)? Write one sentence to justify your answer.

Answer 1

In a previous answer to another of your questions, I provided the steps to draw the Lewis structure. I won't repeat that here.

NO₂^-

N has 5 ve + 6 ve for each O (12 ve) + 1 electron for the - sign = 18 ve

a) two resonance structures are O = N - O and O - N = O (both have a lone pair of electrons on the N and 2 lone pairs around the double bonded O and 3 lone pairs around the single bonded O)

b) For O = N - O formal charges are 0, 0, -1

For O - N = O formal charges are -1, 0, 0

c) The are no double bonds in the true structure as the O = N for each resonance structure is actually a bond and one half. In the experimental structure there is 1 double bond.