© Mr. D. Scott; CHS
Chemical Formula Writing & Nomenclature
 Binary Acids
 Ternary Acids
Basic Rules for acids
 All formulas begin with hydrogen, H
 Those hydrogens listed first are the ones capable of
being ionized when in solution and/or reacted with
bases. Hydrogens listed later in the formula are not
capable of being ionized.
Binary Acids
These follow the format HxAy where A represents some
non-metal element covalently bonded to hydrogen.
Naming Binary Acids
hydro-ic
add prefix root of non-metal name
acid
This naming approach assumes that the acid compound in
aqueous (dissolved in water). When these compounds are
pure, the naming rules follow those of the binary molecules
that we will cover later. Until further notice, we will name
these compounds as acids in aqueous solution.
© Mr. D. Scott; CHS
The oxidation state of the non-metal follows the same
rule as it does when it is combining with a metal. It will
be the first one listed and negative.
Examples:
H+P
H+1 + P-3  H3P hydrophosphoric acid
H+S
H+1 + S-2  H2S
H + Se  H
H+F
+1
+ Se-2  H2Se
H+1 + F-1  HF
hydroselenic acid
hydrofluoric acid
+ Cl-1  HCl
hydrochloric acid
H + Br
H+1 + Br-1  HBr
hydrobromic acid
H+I
H+1 + I-1 
hydroiodic acid
H + Cl  H
+1
hydrosulfuric acid
HI
© Mr. D. Scott; CHS
Ternary Acids
These follow the format Hx(polyatomic ion)y
An important consideration –
All acids are molecules.
While we are using our PAL to combine various polyatomic
ions with hydrogen, these are NOT IONIC COMPOUNDS.
The hydrogen is covalently bonding somewhere on the
polyatomic ion and producing a molecular substance.
Naming Ternary Acids
root of polyatomic name
-ate  -ic
-ite  -ous acid
The ending of the polyatomic name is changed when naming
these acids as indicated above. The rest of the polyatomic
name is not changed.
Not every polyatomic ion will make an acid when combined
with hydrogen. Your knowledge about these will be gained
through experience.
© Mr. D. Scott; CHS
Examples:
H + nitrate 
HNO3
nitric acid
H + nitrite 
HNO2
nitrous acid
H + hypochlorite 
HClO
hypochlorous acid
H + chlorite 
HClO2
chlorous acid
H + chlorate 
HClO3
chloric acid
H + perchlorate 
HClO4
perchloric acid
H + acetate 
HC2H3O2
acetic acid
H + carbonate 
H2CO3
carbonic acid
H + oxalate 
H2C2O4
oxalic acid
H + citrate 
H3C6H5O7
citric acid