What is an Oxoacid?
An oxoacid is a polyatomic ion plus hydrogen.
Polyatomic ions are charged particles that have two or
more atoms held together by covalent bonds.
+ POLYATOMIC ION
The oxoacids that we use in Chemistry 11 Advanced found on
the nomenclature encyclopaedia deal mostly with Nitrogen,
Sulfur, Phosphorous, Chlorine, Bromine and Iodine. Each of
these oxyacids contain at least one hydrogen and one oxygen.
This is what makes them oxoacids. The best way to remember
these elements is to remember that Nova Scotians Play Cards
Better Intoxicated…Nitrogen Sulfur Phosphorus Chlorine
Bromine Iodine.
N-Nova
S-Scotians
P-Play
Hypo…
…ous
Cl-Cards
Br-Better
IIntoxicated
HClO or HOCl
Hypochlorous
acid
HBrO or HOBr
Hypobromous
acid
HIO or HOI
Hypoiodous acid
HClO2 or HO2Cl
Chlorous acid
HBrO2
Bromous acid
HIO2
Iodous acid
HBrO3
Bromic acid
HIO3
Iodic acid
HBrO4
Perbromic acid
HIO4
Periodic acid
…ous
(1 hydrogen)
HNO2
Nitrous acid
(2 Hydrogen)
H2SO3
Sulfurous acid
(3 Hydrogen)
H3PO3
Phosphorous
acid
…ic
HNO3
Nitric acid
H2SO4
Sulfuric acid
H3PO4
HClO3
Phosphoric acid Chloric acid
Per…
…ic
HClO4
Perchloric acid
Look for patterns in this table that will help you remember all the
oxoacids. For example, look at how the number of hydrogens increase by
one in each column for nitrogen, sulfur and phosphorous.
When these oxoacids have a hydrogen in front of them they have no charge. However,
when you take away the Hydrogen in front of the oxyacid, they become ionic and have
a negative charge. For example, HNO2 has no charge because it is an oxyacid, but
when you take away the hydrogen it becomes NO2- with a charge of negative one. The
number of hydrogens in front of the oxyacid determines the charge of the oxyacid.
For example, phosphoric acid,H3PO4, has three hydrogens in front of it. So if you were
to take away the three hydrogens it would leave PO4-3 with a charge of negative three.
This rule applies to all of the oxyacids.
H2CO3 carbonic acid
H2CrO4 chromic acid
H3BO3 boric acid
HCH3CO2 } acetic
CH3COOH} acid
Along with the table these are a
few other important acids you
need to know. All the same rules
apply to these oxyacids as well.
When an oxoacid losses its hydrogen and becomes ionic, its name also changes. If it’s
original ending was ‘ous’ then the new ending will be ‘ite’ and if the original ending
was ‘ic’ then the new ending is ‘ate’. The ACOUSITEICATE disease is a trick that can
help you remember which ending goes with each other if you break it down like this:
AC
OUS
ITE
IC
ATE
-lets you know
that you are
dealing with the
acids
-this is the
original ending
-this is the new
ending replacing
the ‘ous’
-this is the
original ending
-this is the new
ending replacing
the ‘ate’
OUSITE
ICATE
Nitrogen
Sulfur
Phosphorous Chlorine
Bromine
Iodine
ClO- or OClHypochlorite
BrO- or OBrHypobromite
IO- or OIHypoiodite
Hypo…
…ite
…ite
NO2Nitrite
SO3-2
Sulfite
PO3-3
Phosphite
ClO2- or O2ClChlorite
BrO2Bromite
IO2Iodite
…ate
NO3Nitrate
SO4-2
Sulfate
PO4-3
Phosphate
ClO3 Chlorate
BrO3Bromate
IO3Iodate
ClO4Perchlorate
BrO4Perbromate
IO4Periodate
Per…
…ate
The other important acids:
CO3-2 - Carbonate
Cr04-2 - Chromate
BO3-3 - Borate
We hope this slide has helped you better your
understanding of the oxoacids. Once you get
the hang of it, it’s a very easy section.
*Remember the easiest way to remember the
oxoacids is to find your own little patterns and
tricks!!! If you have to make a song, do it!!
