Names to Formulae (3 Types)
1. If it begins with a metal/ammonium, then a nonmetal/polyatomic ion = Ionic compound
a. Write the elements or polyatomic ions in the order listed
b. Find the charges of the cation and anion (check for classic/stock system use)
c. Crisscross charges, reduce, using parentheses around polyatomic ion if needed
2. If it contains two nonmetals (with prefixes) = Covalent compound
a. Write elements in the order listed
b. Turn prefixes into that elements subscripts - do not crisscross
i. if no prefix in front it is assumed to be “mono”
2.
If it ends in “acid”
a. Write an “H” as the cation
b. Use the name to find the anion
i. Hydro_____ic acid = no oxygen (either normal element or cyanide)
ii. _____ic acid = anion is polyatomic ion ending in “ate”
iii. _____ous acid = anion is polyatomic ion ending in “ite”
c. Crisscross charges, using parentheses around polyatomic ion if needed
Formulae to Names (3 Types)
1. If it begins with a metal/ammonium, then a nonmetal/polyatomic ion = Ionic compound
a. For metals with only one possible oxidation state (charge)
i. Write the names in the order listed
ii. Change the end of compound to “ide” if not a polyatomic ion
b. For metals with more than one possible oxidation state
i. Write the metal indicating the present oxidation state using the classic or
stock system
ii. Write the anion, change the end of the compound to “ide” if not a
polyatomic ion
2. If it contains two nonmetals = Covalent compound
a. Write the names in the order listed
b. Turn subscripts into prefixes (mono, di, tri, etc), do not write “mono” on front
c. Change the end of compound to “ide”
3. If it begins with “H” - probably an acid (hydrogen peroxide is the exception)
a. If it does not contain oxygen
i. Form is hydro_____ic acid - anion root goes in the blank
b. If it does contain oxygen
i. Anion ending of “ate” = “ic”; _____ic acid
ii. Anion ending of “ite” = “ous”; _____ous acid
Element
Bromine
Carbon
Chlorine
Fluorine
Hydrogen
Iodine
Nitrogen
Oxygen
Phosphorus
Selenium
Sulfur
Tellurium
Covalent Prefixes:
Mono = 1
Di = 2
Root used in Acid Names
brom
-chlor
fluor
-iod
nitr
-phosphor
selen
sulfur
--
Tri = 3
Tetra = 4
Penta = 5
Hexa = 6
Hepta = 7
Octa = 8
If name ends in “ide”
bromide
carbide
chloride
fluoride
hydride
iodide
nitride
oxide
phosphide
selenide
sulfide
telluride
Nona = 9
Deca = 10
Additional Polyatomic Ions:
The pattern you’ve memorized for chlorine with oxygen polyatomic ions works FOR ALL THE
HALOGENS. The difference is the root above is used in place of “chlor”.
ClOClO2 ClO3 ClO4 -
Hypochlorite
Chlorite
Chlorate
Perchlorate
The pattern you’ve memorized for adding a single hydrogen atom to a polyatomic ion that
creates a new, lower charged ion works for carbonate, sulfate and sulfite.
SO42- = sulfate
HSO4- = bisulfate
Ionic Bonds with Classic and Stock System:
The older system, called the classic system, uses the name of the metal (sometimes in Latin
form) and changes the ending based on whether it is the lower charge or the higher charge. The
lower charge has an ending of “ous” and a higher charge has an ending of “ic”.
The newer system, called the stock system, uses roman numerals in parentheses to show the
number amount of the charge.
I=1
II = 2
III = 3
IV = 4
V=5
VI = 6
VII = 7
VIII = 8
IX = 9
Element
Antimony
Charge
+3
+5
Classic System
Antimonous
Antimonic
Stock System
Antimony(III)
Antimony(V)
Bismuth
+3
+5
Bismuthous
Bismuthic
Bismuth(III)
Bismuth(V)
Chromium
+2
+3
+6
Chromous
Chromic
Chromium(II)
Chromium(III)
Chromium(VI)
Cobalt
+2
+3
Cobaltous
Cobaltic
Cobalt(II)
Cobalt(III)
Copper
+1
+2
Cuprous
Cupric
Copper(I)
Copper(II)
Gold
+1
+3
Aurous
Auric
Gold(I)
Gold(III)
Iron
+2
+3
Ferrous
Ferric
Iron(II)
Iron(III)
Lead
+2
+4
Plumbous
Plumbic
Lead(II)
Lead(IV)
Manganese
+2
+3
+4
+7
Manganous
Manganic
Manganese(II)
Manganese(II)
Manganese(IV)
Manganese(VII)
Mercury
+1
+2
Mercurous
Mercuric
Mercury(I)
Mercury(II)
Nickel
+2
+3
Nickelous
Nickelic
Nickel (II)
Nickel (III)
Tin
+2
+4
Stannous
Stannic
Tin (II)
Tin (IV)