Nitrous oxide, N2O, commonly known
as laughing gas, is used as an anesthetic in minor surgeries, such as the routine
extraction of wisdom teeth. Including lone pairs, give the
structural formula of nitrous oxide.
Our first step will be to determine
the number of valence electrons in nitrous oxide. We can determine the number of
valence electrons for each atom by using the periodic table. Nitrogen has five valence
electrons. And there’s two nitrogens in
nitrous oxide. And oxygen has six valence
electrons. This gives us a total of 16 valence
The next step is to place the atoms
and connect them with single bonds. The atom that we put in the center
should have the most sites available for bonding. In general, this will be the atom
that has the lowest number of valence electrons because it has more electrons needed
to fill its outer shell. This means that we should put one
of the nitrogens in the center.
The next step is to distribute the
remaining electrons so each atom has a full octet, or eight electrons, starting with
the terminal atoms, or the atoms that are on the outside of the structure. Each single bond contains two
electrons, one from each atom participating in the bond. So we have four electrons already
drawn in our structure, meaning that we have 12 electrons remaining to
If we distribute the 12 remaining
electrons to the outside atoms first, we’ll run out of electrons before the nitrogen
in the center has a complete octet. If this happens, we can form
multiple bonds between the atoms by removing a lone pair on one of the atoms that
already has a full octet. So we can remove one of the lone
pairs from the oxygen and put a double bond between the nitrogen and the oxygen.
But nitrogen still doesn’t have a
full octet, so let’s do the same thing to the other nitrogen. Now, we’ve removed a lone pair from
the nitrogen to create a double bond between the nitrogen and the nitrogen. Now, each atom in our structure
contains a full octet. So this is the structural formula
of nitrous oxide, including its lone pairs.