Penguin - 6-3-2005 at 13:45
I need to know how to name acids. How would I know when to name an acid with ous or ic? I also need to know how get a chemical
formula from a name of an acid?
How would I get the chemical formula of hypochlorous acid? And how would I name H3BO3?
Thanks
runlabrun - 6-3-2005 at 14:02
H3BO3 is boric acid
Most acids end in "ic" but for some like hypo acids they end in "ous", so hydrochloric and sulphuric but the hypo acids eg HClO is
hypochlorous acid...
Most are IC, but hypo acids end in OUS.
Acids release a H+ ok? so you need to look at the other bits, not just the releasing H+(s)... SO4(2-) is a sulphate ion, adding 2H+ gives H2SO4,
sulphuric acid... you need to find the radical the acid will leave behind once its fully deprotonated.
PO4(3-) phosphate --> H3PO4 phosphoric acid
PhCOO(1-) benzoate --> PhCOOH benzoic acid
That help some?
-rlr
The_Davster - 6-3-2005 at 14:35
Look at the non hydrogen ion part of the acid. What is it called?
per___ate becomes per____ic acid
______ate becomes ______ic acid
______ite becomes ______ous acid
hypo____ite becomes hypo _____ous acid
(memorize this)
so an example HNO3, it is easily called hydrogen nitrate by IUPAC standards, but since you want classical nomenclature...It is composed of hydrogen
ions (well actually hydronium, but as you are asking about nomenclature, I take it that you are not at that level yet) and nitrate ions when dissolved
in water. So by filling nitrate into the second row of the above table, hydrogen nitrate is nitric acid.
I hope this makes sense.
[Edited on 6-3-2005 by rogue chemist]
[Edited on 6-3-2005 by rogue chemist]
Oxidation states
Kinetic - 6-3-2005 at 15:03
The prefixes and suffixes correspond to the oxidation state of the element upon which the name of the acid is based. A good example to illustrate the
point is the set of oxoacids of chlorine. Bear in mind the following was written by an organic chemist:
The acid with the lowest oxidation state has the prefix hypo, and the suffix ous. For chlorine, this is hypochlorous acid, HClO,
where chlorine is in the +1 oxidation state.
The next in the series has only the suffix ous. For chlorine, this is chlorous acid, HClO2, where chlorine is in the +3 oxidation state.
The next acid has the suffix ic, indicating a more highly oxidised species; for chlorine, this is Cl+5, and the acid is (edit)
chloric acid, HClO3.
The most highly oxidised species has the prefix per, as well as the suffix ic. For chlorine this is of course perchloric acid,
HClO4, with chlorine in the +7 oxidation state.
The same rules apply to other acids; for example, the lowest oxidation state oxoacid of phosphorous is H3PO2, and is called
hypophosphorous acid. The most well-known phosphorus-based acid is phosphoric acid, H3PO4.
[Edited on 6-3-2005 by Kinetic]
AngelEyes - 7-3-2005 at 04:21
One exception to this might be the -ide's.
Chloride, for example, comes from HydroChloric Acid. and -ic acid make an -ide compound. -ate's usually signify that Oxygen is part of the
compound (phosphate, sulphate, nitrate etc)
I just thought this worth mentioning as HydroChloric is quite a common acid.