Unit 4

Inorganic Nomenclature

*Unit 4

*Metals vs Non-Metals

Metals: Form positive ions.Non-metals: Form negative ions. (H is the exception).

• Anion: negatively charged ion (Cl-, O2-, NO3

-).• Cation positively charged ion (K+, Al3+, NH4

+).• Monatomic: only one atom (Ne, Na+, I-).• Diatomic: two atoms (O2, NaCl, I2, LiBr).• Triatomic: three atoms (K2S, O3, H2O).• Polyatomic: many atoms. (Poly means more than one). (CH4, C2H6O,

NaCl)

*Naming Inorganic Particlesa) Naming Monatomic ions

* monatomic metal ions: Place the word ion after the name of the metal.

eg. Potassium metal (K) forms the potassium ion (K+). (monatomic metal ions will have a charge)

* monatomic metal ions with more than one possible combining #:

* place the roman numeral charge value in brackets between the metal name and the word ion.

* eg. Fe3+ = Iron (III) ion, * Fe2+ = Iron (II) ion, * Cu3+ = Copper (III) ion.

* 2) Naming monatomic non-metal ions: *Change the ending of the non-

metal to “ide”. (means negative charge.)

Element name

Symbol Ion name Ion symbol

Fluorine F Fluoride F-

Chlorine Cl Chloride Cl-

Bromine Br Bromide Br-

Iodine I Iodide I-

Oxygen O Oxide O2-

Sulphur S Sulphide S2-

Selenium Se Selenide Se2-

Nitrogen N Nitride N3-

Phosphorus P Phosphide P3-

* b) Naming Polyatomic ions

*Polyatomic ions are compounds that carry a charge.

Carbonate = CO3

2-Nitrate = NO3

- Phosphate = PO4

3-Hydroxide =

OH-

Sulphate = SO4

2-Permanganate

= MnO4-

Chromate = CrO4

2-Acetate =

CH3COO-

Dichromate = Cr2O7

2-Ammonium =

NH4+

*A more complete list:Polyatomic Ion Names SymbolAmmonium NH4

1+

Nitrate NO31-

Nitrite NO21-

Sulfate SO42-

Sulfite SO32-

Bisulfate HSO41-

Carbonate CO32-

Bicarbonate HCO31-

Hydroxide OH1-

Phosphate PO43-

Chlorate ClO31-

Chlorite ClO21-

Permanganate MnO41-

Chromate CrO42-

Dichromate Cr2O72-

*Finding Formulas of Ionic Compounds An Ionic Compound is a compound made of ions.

The 3 Formula Rules:1.Put down the symbols of the ions.

Add brackets around any complex ion.

Write the positive (metallic) ion first. e.g. Ca Cl or Ca(OH)

2. Put combining numbers above each symbol.

e.g. Ca 2+ Cl 1- or Ca 2+ (OH) 1-3. cross out the positive and negative signscriss-cross the combining numbers and use them as

subscripts.

eg. Ca+2 + Cl-1 Ca1Cl2 = CaCl2 or Ca(OH)2

*Notes:*If the subscript is “one”, you don’t need to write it. (Na1Cl1 = NaCl)*You must reduce subscripts if possible. Is there a number that will divide evenly into both subscripts? (i.e. Mg2O2 = MgO)*Subscripts inside brackets of complex ions must NOT be changed*eg. Ca 2+ + NO3

1- Ca(NO3)2 *If the subscript outside brackets is one, don’t write the brackets *eg. Na(OH)1 NaOH

*More Than One Combining Capacity

Lead (IV) Oxide: Pb+4 O-2 Pb2O4 = PbO2

Lead (II) Oxide: Pb+2O-2 Pb2O2 = PbO

*Try these examples on your own:

1. magnesium and oxygen__

Mg2O2 MgO

2. potassium and sulphate___________

K2SO4

3. hydrogen and fluorine___________HF

4. calcium and hydrogen____________

CaH2

*Naming Ionic Compounds

A. Binary Compounds / Only two elements /a metal and a non-metal

To name: a) Name the metal first without changing its name

b) Name the non-metal second and change its ending to ide

E.g. BeBr2 = Beryllium bromide

*Write the formula, then the name:

Sodium and Bromine ________________ __________________

Potassium and Oxygen ______________ ______________________

*Write the formula, then the name:

Sodium and Bromine ____________NaBr

__Sodium Bromide___________

Potassium and Oxygen __________

K2O

__Potassium Oxide___

B. Compounds containing elements with more than one combining capacity

-Some elements can have multiple charges/comb. #s -Use Roman numerals to specify which ion it is:Eg Fe(II) = Fe 2+ Look at the periodic table

Fe(III) = Fe 3+ see more than one comb cap

To name: a) find combining # by reverse criss-cross

b) change combining # to roman numeral, put after metal name

*Only metals can form more than one possible type of ion*

E.g. FeCl2 = Fe 2+ and Cl1- = _Iron (II) Chloride_____________________

Write the formula, then the name:

* Iron (II) and Oxygen _________FeO

__Iron (II) Oxide___

* Copper (I) and Bromine ______CuBr

_Copper (I) Bromide

Charged Groups of Atoms (Polyatomic Ions)

To name: Refer to your Periodic Table of Common Ions

Put: 1. positive ion first.

2. negative ion second.

E.g. Ba 2+ + SO42- = BaSO4 = Barium sulphate

E.g. Ba 2+ + PO43- = Ba3(PO4)2 = Barium

phosphate

*Write the formula, then the name:

Potassium and Bicarbonate _________KHCO3__

Potassium Bicarbonate _

Magnesium and Nitrate _______Mg(NO3)2__

__Magnesium Nitrate

*Class work: p. 71 – 72

*#4. a – o

*#5. a – o

*Naming HydratesCrystals of ionic compounds often have water “stuck” to them.

eg. when Copper (II) Sulphate is crystallized from a water solution, the resulting crystals have the formula:

CuSO4 · 5H2O

5 water molecules are attached to every CuSO4

the waters attached are called “Hydrates”

prefixes are used to tell the number of Hydrates attached

Prefix Used # of water molecules

mono 1

di 2

tri 3

tetra 4

penta 5

hexa 6

hepta 7

octa 8

nona 9

deca 10

Hydrate name = compound name + prefix + “hydrate”

eg. name of CuSO4 · 5H2O = “copper (II) sulfate pentahydrate”

Ca(NO3)2 · 4H2O =

“calcium nitrate tetrahydrate”

Homework: p. 73

#6. a,c,e,g,i

#7. a,c,e,

*Naming Binary Compounds

*usually are covalently bonded molecules

*composed of two different types of atoms

*it is assumed one particle is cation-like and the other is anion-like

*Naming Binary Compounds:

1. Use prefix system (mono, di, tri, …)

2. Cation-like element written 1st, anion-like element written 2nd

3. Ending of name changed to “ide”

eg. CO = Carbon monoxide.

*What about P2S3?4. Place prefix, according to the number of that atom within the

molecule, in front of the elements’ name

So P2S3 is written: “Diphosphorus trisulphide”

****exception: if only one atom in cationic spot, then do not place the prefix mono in front of the elemental name.

eg. NO2 = Nitrogen dioxide, not mononitrogen dioxide.

*Practice:* NCl3 =

Nitrogen trichloride.

* P4O6 =

Tetraphosphorus hexaoxide.

* S2F2 =

Disulphur difluoride.

* NI3 =

Nitrogen triiodide.* ICl =

Iodine monochloride.

*Homework p. 74 #8 a,c,e,g* #9 a,c,e,g,i

*Naming Common Acids

An acid is a compound starting with an H (hydrogen), and has a pH < 7.

Most acids contain: oxygen, hydrogen a non-metal. When dissolved in water, an acid breaks apart:

H+“anion” +

acid

eg: HNO2 + water → NO2- + H+

acid anion

*Common acids:ACID ANION

HF Hydrofluoric acidHCl Hydrochloric acidHBr Hydrobromic acidHI Hydroiodic acidHNO2 Nitrous acid NO2

- Nitrite ion

HNO3 Nitric acid NO3- Nitrate ion

H3PO4 Phosphoric acid PO43- Phosphate ion

H2SO3 Sulphrous acid SO32- Sulphite ion

H2SO4 Sulphuric acid SO42- Sulphate ion

HClO Hypochlorous acid ClO- Hypochlorite ion

HClO2 Chlorous acid ClO2- Chlorite ion

HClO3 Chloric acid ClO3- Chlorate ion

HClO4 Perchloric acid ClO4- Perchlorate ion