2.5: Nomenclature

        

1. MOLECULAR COMPOUNDS
(Non-metal + Non-metal)

①Name first element first, then for the second element add the suffix "-ide". Use Greek prefixes to indicate the number of atoms each element has in the compound.

Greek Prefix:

Mono - 1

Di - 2

Tri - 3

Tetra - 4

Penta - 5

Hexa - 6

Hepta - 7

Octa - 8

Nona - 9

Deca - 10

Example: 

N₂O --> Dinitrogen Monoxide

CO --> Carbon Monoxide

IF₆ --> Iodine Hexafluoride

P₄S₁₀ --> Tetraphosphorous decasulfide

2. IONIC COMPOUNDS

a) Binary: Metal + Non-metal

①Representative (A) elements: name of the (+) Ion, followed by the name of the (-) Ion + suffix "-ide"

Example:

NaCl --> Sodium Chloride

MgCl₂ --> Magnesium Chloride

②Transition (B) elements: name of the metal + roman number indicating charge + name of non-metal with "-ide" suffix

Example:

Fe⁺³ --> Iron (III)

FeCl₂ --> Iron (II) Chloride

③Positive Ions (Cations): Name of the element + "ion"

Example:

Li⁺ --> Lithium Ion

Mg⁺² --> Magnesium Ion

④Negative ions (Anions): Name of the element + suffix "-ide" + "ion"

Example:

Cl⁻ --> Chloride ion

S⁻² --> Sulfide ion

b) Ternary: Metal + Polyatomic / Polyatomic + Polyatomic


POLYATOMICS

2 Oxygen less Hypo_____ite	1 Oxygen less ______ite	COMMON POLYATOMICS	1 more Oxygen Per_____ate
NO⁻ (Hyponitrite)	NO₂⁻ (Nitrite)	NO₃⁻ (Nitrate)	NO₄⁻ (Pernatrate)
ClO⁻ (Hypochlorite)	ClO₂⁻ (Chlorite)	ClO₃⁻ (Chlorate)	ClO₄⁻ (Perchlorate)
CO⁻² (Hypocarbonite)	CO₂⁻² (Carbonite)	CO₃⁻² (Carbonate)	CO₄⁻² (Percarbonate)
SO₂⁻² (Hyposulfite)	SO₃⁻² (Sulfite)	SO₄⁻² (Sulfate)	SO₅⁻² (Persulfate)
PO₂⁻³ (Hypophosphite)	PO₃⁻³ (Phosphite)	PO₄⁻³ (Phosphate)	PO₅⁻³ (Perphosphate)

Note: Rules don’t apply to all polyatomics‼

OTHER POLYATOMICS

NH₄⁺ (Ammonium)

OH⁻ (Hydroxide)

HCO₃⁻ (Bicarbonate)

CH₃COO⁻ (Acetate)

Example:

Ca(OH)₂ --> Calcium Hydroxide

(NH₄)₂O --> Ammonium Oxide

(NH₄)₂SO₄ --> Ammonium Sulfate

CaSO₄ --> Calcium Sulfate

ACIDS

a) Binary: H + Non-metal

①Hydro + name of the element + suffix "-ic" + acid


Example:


HCl --> Hydrochloric Acid
HF --> Hydrofluoric Acid
H₂S --> Hydrosulfuric Acid

b) Ternary / Oxyacid: H + Polyatomic

①"-ATE" Ending: Replace "-ate" by "-ic" + "acid"

Example:

H₂CO₃ --> Carbonic Acid

H₃PO₄ --> Phosphoric Acid

②"-ITE" Ending: Replace "-ite" by "-ous" + "acid"

Example:

H₂SO₃ --> Sulfurous Acid

HNO₂ --> Nitrous Acid