1. Which is the correct Lewis structure of nitrite ion, NO2-?
QUESTION:
Which is the correct Lewis structure of nitrite ion, NO2-?
Nitrogen and oxygen are second-row elements so they follow the octet rule.
Let’s see if all the atoms in these structures obey the octet rule.
SCRIPT FOR SLIDE 1
Question. Which of the structures given is the correct Lewis structure of the nitrite ion, n o 2 minus?
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we know that nitrogen and oxygen, as second-row elements, will follow the octet rule.
So let’s see if all the atoms in these structures obey the octet rule.

2. Not a valid Lewis structure
O 2 bonds x 2 4 electrons
2 lone pairs x 2 4 electrons
8 electrons
N 4 bonds x 2 8 electrons
1 lone pair 2 electrons
10 electrons
Not a valid Lewis structure
O 1 bonds x 2 2 electrons
3 lone pairs x 2 6 electrons
8 electrons
N 3 bonds x 2 6 electrons
1 lone pair 2 electrons
SCRIPT FOR SLIDE 2
We’ll start with structure a.
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The oxygens in structure a both have two bonds.
giving four electrons and
2 lone pairs giving another four electrons
for a total of eight electrons. So the oxygens obey the octet rule.
The nitrogen
has four bonds, giving eight electrons
and one lone pair, giving two more electrons
for a total of ten electrons.
The nitrogen violates the octet rule so structure a
Is not a valid Lewis structure.
What about b?
Here we again have a double-bonded oxygen with two lone pairs. We already determined above
that this follows the octet rule. What about the other oxygen?
It has one bond, giving two electrons and
Three lone pairs, giving 6 electrons for a total of
eight electrons. So this oxygen follows the octet rule.
What about the nitrogen?
Nitrogen has three bonds, giving six electrons and
one lone pair giving two for a total
of eight electrons. The nitrogen obeys the octet rule as well as both oxygens, so this is a valid Lewis structure.
Is a valid Lewis structure

3. Not a valid Lewis structure
O 1 bonds x 2 2 electrons
3 lone pairs x 2 6 electrons
8 electrons
N 2 bonds x 2 4 electrons
1 lone pair 2 electrons
6 electrons
Not a valid Lewis structure
O 3 bonds x 2 6 electrons
2 lone pairs x 2 4 electrons
10 electrons
N 5 bonds x electrons
0 lone pair 0 electrons
SCRIPT FOR SLIDE 3
Structure c
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As in b we have oxygens with
one bond
and three lone pairs.
These follow the octet rule. The nitrogen in this structure has
2 bonds, giving four electrons and
one lone pair giving two electrons
for a total of six. The nitrogen here violates the octet rule so
c is not a valid Lewis structure.
What about d?
We have an oxygen with two bonds and two lone pairs,
which we saw on the previous slide does follow the octet rule. The second oxygen has three bonds
giving 6 electrons and
two lone pairs giving four electrons for a total
of 10 electrons.
The nitrogen has five bonds
giving ten electrons
and zero lone pairs
giving ten electrons total. Both the oxygen and the nitrogen violate the octet rule so
structure d is not a valid Lewis structure.
Not a valid Lewis structure

4. Which is the correct Lewis structure of nitrite ion, NO2-?
QUESTION:
Which is the correct Lewis structure of nitrite ion, NO2-?
SCRIPT FOR SLIDE 4
The only structure in which all atoms followed the octet rule was b, so b
CLICK
is the correct answer.

5. Video ID: 3-5-JJW © 2008, Project VALUE (Video Assessment Library for Undergraduate Education), Department of Physical Sciences Nicholls State University Author: Jeremy Wessel Narrator: Cynthia Lamberty Funded by Louisiana Board of Regents Contract No. LA-DL-SELECT-13-07/08