Ionic Nomenclature

Cation

Defn: A positively charged particle.

Name of metal+ the word “ion”.

Ex. Potassium

Potassium Ion

Anion

Defn: a negatively charged particle.

Name of non-metal w/ ending changed

to “ide”

Ex. Chlorine

Chloride

Binary Ionic Compounds

Contains only 2 different elements in the

compound

Naming the Compounds

Name of metal + Name of non-metal with “ide”

ending.

Ex NaCl

Sodium Chloride

More Examples

MgO

Magnesium Oxide

MgCl2

Magnesium Chloride

LiBr

Lithium Bromide

Ca3P2

Calcium Phosphide

Transition Metals

Transition metals can give up different

numbers of electrons

Therefore they can have multiple charges

(This applies to lead and tin, too.)

Ex. If Titanium loses 3e- Ti3+

Roman Numerals

Tells the charge of the ion preceding it. When an ion

can have more than one charge, you need to use a

roman numeral to specify the charge.

Ex Lead

Pb2+

Lead (II) ion

Pb4+

Lead (IV) ion

Exceptions

If the transition metal only has one charge,

then DO NOT use a roman numeral!

Ex. Zinc

Zn2+ Zinc ion

What are other examples of a transition metal

with only one charge?

Ag+, Cd2+, Sc3+

Reminder

Roman numerals tell the charge of an

ion, NOT HOW MANY!

Ex. Gold (III) chloride

What is the charge of the gold ion in gold

(III) chloride?

3+

Example:

Tin (II) bromide

What is the charge of the tin ion in tin

(II) bromide?

2+

Writing Formulas

The positive and negative charges must equal ZERO in

the compound.

1. Write the symbol and charge for each individual ion

2. Use the least common denominator (LCD) to determine

how many of each ion is needed in order to make a zero

net charge.

3. Write the formula, using a subscript(s) to indicate the

number of each ion in the compound

Example

Zinc sulfide

Zn2+ S2-

ZnS

Example

Sodium Oxide

Na+ O2-

Na2O

Example

Scandium bromide

Sc3+ Br –

ScBr3

Naming ionic compounds with polyatomic ions

(tertiary ionic compounds):

1. Name of cation first

2. Name of anion second

3. Remember roman numerals, if necessary

4. Enclose polyatomic ions in parenthesis when

it requires a subscript

Example

Zn2+ SO42-

Balanced Formula?

ZnSO4

Name?

Zinc sulfate

Calcium Phosphate

Ca2+ PO43-

Balanced Formula?

Ca3(PO4)2

Name?

Calcium Phosphate

Manganese (IV) Nitrite

Mn4+ NO2-

Balanced Formula?

Mn(NO2)4

Name?

Manganese(IV) Nitrite

MgCl2

CuSO4

Example: Copper (I) Chlorate

Cu+ ClO3-

Balanced Formula?

CuClO3

Name?

Copper (I) Chlorate

Chromium (III) Hydroxide

Cr3+ OH-

Balanced Formula?

Cr(OH)3

Name?

Chromium(III) hydroxide

NaNO3

Al(OH)3

Cu3PO4

Covalent Nomenclature

aka Molecular Compounds

To Name Covalent Compounds:

1. Translate the subscript of the first element into

a prefix + the name of the element

2. Translate the subscript of the 2nd element into a

prefix + root name of element with the “ide”

ending1 Mono 4 Tetra 7 Hepta

2 Di 5 Penta 8 Octa

3 Tri 6 Hexa 9 Nona

10 Deca

NOTE

If there is only 1 of the 1st

element, do not use a prefix

Ex. CO

carbon monoxide

Name the Following Compounds

N2O

Dinitrogen monoxide

PCl3

Phosphorus trichloride

SF6

Sulfur hexafluoride

Name the Following Compounds

CO2

Carbon dioxide

NO

nitrogen monoxide

CCl4

carbon tetrachloride

To Write Formulas for Covalent Compounds:

1. Correlate the prefix of the 1st element to its

numerical value…write it as the subscript

2. Correlate the prefix of the 2nd element to its

numerical value…write it as the subscript

3. Prefix should match the subscript written for

each element

*Remember, if there is not a prefix, then it’s just 1.

Write the formula for each

Tetraiodine nonoxide

I4O9

Sulfur trioxide

Phosphorus pentafluoride

Write the formula for each

Nitrogen dioxide

NO2

Dichlorine heptoxide

Cl2O7

Carbon disulfide

CS2

Acid Nomenclature

Naming Acids

Acids always have hydrogen.

Binary Acids

Hydrogen + 1 other element

Oxy Acids

Hydrogen + oxygen (from a polyatomic

ion)

Binary Acids

1. Use “hydro” for hydrogen

2. Root of 2nd element + ic (take off the

ending)

3. add “acid” to the end

Ex : HCl

Hydrochloric acid

Name the Binary Acids

H2S

Hydrosulfuric acid

(notice here that it is sulfuric, not sulfic)

HF

Hydrofluoric acid

HBr

Hydrobromic acid

Oxy Acids “ite”

The name of the acid comes from the name of the

polyatomic ion.

If the polyatomic ion ended in “–ite”, then the ending for the

acid is “–ous”

Take off the “ite” ending of the polyatomic ion and add

–”ous”

Add the word “acid”

Ex. HNO2

Nitrous Acid

Name the oxy acids

H2SO3

Sulfite Ion

Sulfurous acid

H3PO3

Phosphite Ion

Phosphorous acid

Oxy Acids “ate”

If the polyatomic ion ended in “–ate”, then the ending

for the acid is “–ic”

Take off the “ate” ending of the polyatomic ion and add

–”ic”

Add acid

Ex. HNO3

nitrate ion

Nitric acid

Name the oxy acids

H2SO4

Sulfate ion

Sulfuric Acid

H3PO4

Phosphate ion

Phosphoric Acid

Writing formulas for binary acids

Determine what kind of acid it is; binary or

oxy

Does it have hydro at the front?

If yes, then it is binary

Determine the charges for the individual ions

Write the formula so that the overall charge

equals zero

Example

Hydroiodic acid

H+ I-

HI

Hydroselenic acid

H+ Se2-

H2Se

Writing formulas for oxy acids

Determine what kind of acid it is; binary or

oxy

Does it have -ous or –ic at the end?

If yes, then it is an oxy acid

Determine the charges for the individual ions

Write the formula so that the overall charge

equals zero

Example

Chlorous acid

from chlorite ion

ClO2- HClO2

Boric acid

From borate ion

BO33-

H3BO3

Chloric acid

from chlorate ion

ClO3- HClO3

Examples

Sulfurous acid

from sulfite ion,

SO32- H2SO3

Carbonic acid

from carbonate ion,

CO32- H2CO3