Chapter 3 Section 3.5 Guideline #5 Tasks #9 & #10

Binary -Ternary Acids Names and Formulas


         Fifth guideline (Not in the Book)

Compounds which have Hydrogen written first in
the formula and are in
aqueous solutions (aq)
are known as Binary and Ternary Acids

HClO4 (aq) Perchloric Acid

HClO3 (aq) Chloric Acid

HClO2 (aq) Chlorous Acid

HClO (aq) Hypochlorous Acid

HCl (aq) Hydrochloric Acid



Acids are classified as Strong Acids and Weak Acids (Chapter 10)

Strong Acids Weak Acids

Strong acids ionize 100% in a water solution, while
Weak Acids ionize less than 5% in a water solution.


A brief tutorial for names and formulas of acids follows:

If hydrogen is written first in a chemical formula, there are two ways to name the compound.

1. As a pure molecular compound or
2. As
an aqueous acid:

Step #1: If the compound is a pure molecular compound then you name it just as if it were an ionic compound:

HCl          hydrogen chloride H3PO4     hydrogen phosphate

HClO        hydrogen hypochlorite H2SO4     hydrogen sulfate

HClO2      hydrogen chlorite H2SO     hydrogen sulfite

HClO3      hydrogen chlorate HBr hydrogen bromide

HClO4      hydrogen Perchlorate HF hydrogen fluoride

H2CO3     hydrogen carbonate HI hydrogen iodide

HC2H3O2   hydrogen acetate  H2C2O4 hydrogen oxalate


Writing hydrogen first in a chemical formula indicates that when you dissolve the compound in water, a water molecule has the ability to pull the hydrogen off (from strong electronegative elements like oxygen)  the molecule HXO3 and creating hydronium ions, H3O1+ and  a negative ion XO31- (cation).

The way you indicate this ionic solution is to write the formula followed by (aq) meaning a water solution:  HXO3 (aq) .

Step #2 is to drop the first word hydrogen and
add a second word

HCl          hydrogen chloride acid (aq)

HClO        hydrogen hypochlorite acid (aq)

HClO2      hydrogen chlorite acid (aq)

HClO3      hydrogen chlorate acid (aq)

HClO4      hydrogen perchlorate acid (aq)

H3PO4     hydrogen phosphate acid (aq)

H2CO3     hydrogen carbonate acid (aq)

H2SO4     hydrogen sulfate acid (aq)

H2SO3     hydrogen sulfite acid (aq)

HC2H3O2   hydrogen acetate acid (aq)

H2C2O4 hydrogen oxalate acid (aq)

HBr hydrogen bromide acid (aq)

HF hydrogen fluoride acid (aq)

HI hydrogen Iodide acid (aq)

Step #3 is to drop the suffix from the ANION and make the following substitution with another suffix:

Change the -ate to -ic

Change the -ite to -ous

but instead of coming up with a third suffix for -ide ,
they reused the
-ic for -ide and added a prefix hydro-
(Do not get this confused with the prefix hypo- which means 'under'.)


HCl         hydrochloric  acid (aq)

HClO       hypochlorous acid (aq)

HClO2      chlorous acid (aq)

HClO3      chloric  acid (aq)

HClO4      perchloric  acid (aq)

H3PO4     phosphoric  acid  (aq) (Put the -or- syllable back in the name)

H2CO3     carbonic  acid (aq)

H2SO4     sulfuric  acid  (aq) (Put the -ur- syllable back in the name)

H2SO3      sulfurous acid (aq) (Put the -ur- syllable back in the name)

HC2H3O2   acetic  acid (aq(Notice the three hydrogens written after carbon are
NOT ionizable and not written first in the formula)

H2C2O4 oxalic acid (aq)

HBr hydrobromic acid (aq)

HF hydrofluoric acid (aq)

HI hydroiodic acid (aq)


Chapter 3 Section 3.5 Guideline #5 Tasks #9 & #10

Task #9 Names of Binary-Ternary Acids


Task #10 Formulas of Binary-Ternary Acids