The same story holds for nitrogen. If a
ion were introduced into water, it would instantly pull the lone
electron pairs on the oxygen atoms of water molecules toward itself
so strongly that the water protons would be released, leaving nitrate
These ions are shown on the right.
ion would not be satisfied merely with sharing lone pairs from water
oxygens in covalent bonds. Fluorine is so electronegative that it
would strip the lone pairs completely off the water molecules, picking
up four such electron pairs to yield
ions (right). The wreckage of the water molecules would remain as
is an imaginary ion, something like this reaction actually occurs
is added to water, as we will see later in this chapter.
These all have been hypothetical experiments (except for
but the products are real. The most stable forms of the common oxides
of second-shell elements in water solution are the following ions:
The purpose of these imaginary experiments has been to show, in
terms of electronegativities and electron-pulling power, why each
of the ions above is the prevalent species in solution. With these
in mind, we now can turn to the acid-base behavior of the oxides.