Inorganic Nomenclature

Naming CompoundsWriting Formulas

Systematic Naming

There are more than 50 million named chemical substances

Many have common names that we use everyday like sugar, table salt, borax, and sand

They all have systematic names that make keep track of them easier and uniquely identify each one.

Compounds

Follow the Law of Definite Proportion.Have a constant composition.Same formula (atoms) every timeTwo Major Types of Compounds

Ionic Covalent or Molecular

Molecular Compounds

Covalent Compounds Made of moleculesMade by joining nonmetal atoms

together into moleculesNon-Metal Non-Metal

Combinations Soft solids, liquids, and gases Carbon dioxide CO2Dihydrogen monoxide H2O

Ionic Compounds

Made of cations and anionsPositive ion bonded to negative ionMetal Non-Metal CombinationsThe electrons lost by the cation are

gained by the anionThe cations and anions surround

each otherSmallest ratio of ions in an ionic

compound is a FORMULA UNIT.All hard, brittle solids Calcium chloride CaCl2

K+1

Ca+2 Has lost two electrons

Cations

Positive ionsFormed by losing electronsMore protons than electronsMetals usually

Has lost one electron

AnionA negative ionHas gained electronsNon metalsCharge is written as a superscript

on the right.

F-1 Has gained one electron

O-2 Has gained two electrons

Chemical Formulas

Shows the kind and number of atoms in the smallest piece/ratio of a substance

CO2 C6H12O6AlBr3

Formula Unit

The smallest whole number ratio of atoms in an ionic compound.

Ions surround each other so you can’t say which is hooked to which

Two systems for naming inorganic compounds The Stock (Roman numeral) System

used for Ionic Compounds

The Numerical Prefix System used for Covalent Compounds

General Rules for Roman # SystemWrite the name of the less

electronegative element or polyatomic ion

Write down the name of the other element or polyatomic ion

Put a Roman numeral in parentheses after the first element name The Roman numeral is equal to the

oxidation state (charge) of the first element

Rules for Binary Compounds Composed of 2 different elements Write down the name of the less

electronegative element (metal) Write down the root of the other

element then add ---ide to the end. Place the roman numeral in

parentheses after the first element if needed Roman # equals the charge of the first

element

Determining Charges on ionsFor Elements in Groups 1, 2,13-18

on the Periodic Table you can tell what kind of ion they will form from their location on the table

Elements in the same group have similar properties

Including the charge when they are ions

+2+1

+3 -3 -2 -1

What about the others?

We have to figure those out some other way.

More on this later.

Naming Ions

We will use the systematic wayCation- if the charge is always the

same just write the name of the metal (Gr. 1, 2, 13)

Transition metals can have more than one type of charge

Indicate the charge with a Roman numeral in parentheses

How we determine this in a bit

Name these

Na+1 Ca+2 Al+3 Fe+3 Fe+2 Pb+2 Li+1

Write Formulas for these

Potassium ionMagnesium ion Copper (II) ionChromium (VI) ionBarium ionMercury (II) ion

Naming Anions

Anions are always the same when it comes to charge

Change the element ending to – ideF-1 fluorideS-2 sulfideP-3 phosphideTe-2 telluride

Name these

Cl-1

N-3

Br-1

O-2

Ga+3

Write these

Sulfide ion iodide ionphosphide ionStrontium ion

Polyatomic ionsGroups of atoms that stay

together and have a chargeYou must memorize these or use

an ion sheetAcetate C2H3O2

-1

Nitrate NO3-1

Nitrite NO2-1

Hydroxide OH-1Permanganate MnO4

-1 Cyanide CN-1

Polyatomic ionsSulfate SO4

-2

Sulfite SO3-2

Carbonate CO3-2

Chromate CrO4-2

Dichromate Cr2O7

-2

Phosphate PO4-3

Phosphite PO3-3

Ammonium NH4

+1

Hints for Naming Polyatomic Ions

Ending Formula

Name (from the element that is not oxygen)

Chlorine Formula

---ide No oxygen

S-2 Sulfide Chloride Cl-1

---ite Some oxygen

SO3-2 Sulfite Chlorite ClO2-1

---ate More oxygen

SO4-2 Sulfate Chlorate ClO3-1

Hypo--- ---ite

Less oxygen

Hypochlorite

ClO-1

Per--- -----ic

Most oxygen

Perchlorate ClO4-1

Naming Ionic Compounds

Binary Ionic Compounds (salts)Binary Compounds

2 elements Metal nonmetal a cation and an anion + -

To write the names just name the two ions.

Groups 1, 2, 13

Easy with Representative elements Groups 1, 2, 13 Charge determined by location in table

NaCl = Na+ Cl- = sodium chlorideMgBr2 = Mg+2 Br- = magnesium

bromide

Naming Binary Ionic Compoundswith Variably Charged Cations

The problem comes with the transition metals and in other variable charged cations

Elements not are not in groups 1, 2 , or 13. Need to figure out their charges.

How?

How do we figure out the roman numeral? The compound must be neutral Same number of + and – charges Look up the charge on the negative Calculate the total negative charge Must be equal to total positive

charge Divide positive total by number of

atoms Result is equal to charge on positive This is the Roman numeral

Example: Determining the Roman Numeral

Write the name of CuOCopper is not in gr 1, 2, or 13 so

need a roman numeral O is -2 thereforeCopper must be +2 so the roman

numeral = 2Name is Copper (II) chloride

Another in Class ExampleName the following:

CoCl3

Another Example Write the name of Cu2S

Last Example

Fe2O3

Naming Binary Ionic Compounds Write the names of the following KCl Na3N CrN Sc3P2 PbO PbO2

Na2Se

Ternary Ionic Compounds Will have at least one polyatomic ions At least three elements Name the ions: Use a roman numeral if needed. NaNO3

CaSO4

CuSO3

(NH4)2O

Ternary Ionic Compounds

LiCN

Fe(OH)3

(NH4)2CO3

NiPO4

Writing Formulas Given the name write the formula

Things to remember: The charges in a compound have to add

up to zero1. Write down each ion with charges2. Make the charges equal by adding

subscripts3. Put polyatomic ions in parentheses

before using a subscript

Writing Formulas ExampleWrite the formula for calcium

chloride.Calcium is Ca+2 Chloride is Cl-1 Charge on compound must be 0. So 2 Cl-1 are needed to make the

charge = to zero.CaCl22 atoms of chlorine for every one atom of calcium

Another Example

Aluminum nitrate

Write the formulas for theseLithium sulfidetin (II) oxidetin (IV) oxideMagnesium fluorideCopper (II) sulfateIron (III) phosphide

Write the formulas for thesegallium nitrate Iron (III) sulfide

Ammonium chloride

ammonium sulfide

barium nitrate

Things to look for

If cation has a (Roman Numeral), the number is the charge of the positive ion

If anions end in -ide they are probably off the periodic table (monoatomic) but can be cyanide, hydroxide

If anion ends in -ate or -ite it is polyatomic

Molecular CompoundsWriting names and Formulas

Molecular compounds

Nonmetal Nonmetal combinationssmallest piece is a moleculeAlso called covalent compoundsnot held together because of

opposite charges

Easier

Molecular compounds name tells you the number of atoms

Uses prefixes to tell you the number

Prefixes

1 mono-2 di-3 tri-4 tetra-5 penta-6 hexa-7 hepta-8 octa-

Prefixes

9 nona-10 deca-

Prefixes

9 nona-10 deca-To write the name write two words

Prefix name Prefix name -ide

Prefixes

9 nona-10 deca-To write the name write two words

One exception is we don’t write mono- if there is only one of the first element.

Prefix name Prefix name -ide

Prefixes9 nona-10 deca-To write the name write two words

One exception is we don’t write mono- if there is only one of the first element.

No double vowels when writing names (oa oo) except with i

Prefix name Prefix name -ide

Name These

N2O

NO2

Cl2O7

CBr4

CO2

BaCl2

Write formulas for these

diphosphorus pentoxide tetraiodide nonoxide sulfur hexaflouride nitrogen trioxide carbon tetrahydride phosphorus trifluoride aluminum chloride

AcidsWriting names and Formulas

Acids

Compounds that give off hydrogen ions when dissolved in water.

Must have H in themwill always be some H next to an

anionHClH2SO4The anion determines the name

Anions/AcidsAnion Example Acid Example

….ide Cl- 1

chloride Hydro…ic HCl

Hydrochloric acid

…..ite ClO2- 1

chlorite ….ous HClO2

Chlorous acid

Hypo…..ite ClO-1

hypochloriteHypo….ous HClO

Hypochlorous acid

…..ate ClO3- 1

chlorate ….ic HClO3

Chloric acid

Per…ate ClO4- 1

perchlorate Per……ic HClO4

Perchloric acid

Naming acids: Three Rules Rule 1: If the anion attached to

hydrogen is ends in -ide, put the prefix hydro- and change -ide to -ic acid Example: HCl - hydrogen ion and

chloride ion

Example: H2S hydrogen ion and sulfide ion

Naming OxyAcids

If the anion has oxygen in it it ends in -ate of -ite

Rule 2: change the suffix -ate to -ic acid

Example: HNO3 Hydrogen and nitrate ions

Rule 3: change the suffix -ite to -ous acid Example: HNO2 Hydrogen and nitrite

ions

Name these

HFH3PH2SO4 H2SO3 HCNH2CrO4

Writing Formulas

Hydrogen will always be firstname will tell you the anionmake the charges cancel out.Rule 1: hydro- no oxygen, -ide

ion

Rule 2 : no hydro, -ate comes from -ic,

Rule 3: no hydro -ite comes from -ous

Write formulas for these

hydroiodic acid

acetic acid

carbonic acid

phosphorous acid

hydrobromic acid

Hydrates

A solid compound with a specific number of water molecules bonded to it

Release water when heated at fairly low temperatures

Anhydrous Solid•xH2O) Common Example: CuSO4 5H2OCopper (II) sulfate pentahydrateThe penta indicates five water

molecules for each copper (II) sulphate particle

Prefixes

The prefix indicates the number of water molecules bonded to the anhydrous salt

Name to Formula

zinc sulphate heptahydrate copper (I) sulphite monohydrate cobalt (II) fluoride tetrahydrate  lithium nitrate trihydrate sodium sulphate decahydrate calcium nitrate trihydrate 

Formula to Name

Na2SO4  10H2O LiNO3  3H20 Cu2SO3  3H20 Ca(N03) 2  2H20 MgS04  7H20 ZnS04  7 H20