CHEMICAL FORMULAS

CO2 Has 2 elements: carbon and oxygen

Has 3 atoms 1 C atom and 2 O atoms

C6H12O6 Has 3 elements, and 24 atoms

NAMING IONIC COMPOUNDS

First word NaCl

Cation-(positive ion) if the charge is always the same write the name of the metal.

Transition metals can have more than one type of charge.

Indicate the charge with Roman numerals in parenthesis.

NAME THESE

Na+1

Ca+2

Al+3

Fe+3

Fe+2

Pb+2

Li+1

Second Word NaCl

Anions (negative ion) are always the same charge.

Change the element ending to – ide

Cl-1 Chloride

NAME THESE

Cl-1

N-3

Br-1

O-2

Ga+3

WRITE THESE

Sulfide ion

iodide ion

phosphide ion

Strontium ion

POLYATOMIC IONS

Groups of atoms that stay together and have a charge.

Acetate C2H3O2-1

Nitrate NO3-1

Nitrite NO2-1

Hydroxide OH-1

Permanganate MnO4-1

Cyanide CN-1

NAMING BINARY IONIC COMPOUNDSBinary Compounds - 2 elements.

Ionic - a cation and an anion.

To write the names just name the two ions.

Easy with Representative elements.

Group A

NaCl = Na+ Cl- = sodium chloride

MgBr2 = Mg+2 Br- = magnesium bromide

NAMING BINARY IONIC COMPOUNDS

The problem comes with the transition metals.

Need to figure out their charges.

The compound must be neutral.

same number of + and – charges.

Use the anion to determine the charge on the positive ion.

NAMING BINARY IONIC COMPOUNDSWrite the name of CuO

Need the charge of Cu

O is -2 copper must be +2

Copper (II) oxide

Name CoCl3

Cl is -1 there are three of them = -3

Co must be +3

Cobalt (III) chloride

NAMING BINARY IONIC COMPOUNDSWrite the names of the following

KCl

Na3N

CrN

Sc3P2

PbO

PbO2

Na2Se

POLYATOMIC IONS IN COMPOUNDS

At least three elements

NaNO3

CaSO4

CuSO3

(NH4)2O

LiCN

Fe(OH)3

(NH4)2CO3

NiPO4

WRITING FORMULAS

The charges have to add up to zero.

Get charges on pieces.

Cations from name of table.

Anions from table or polyatomic.

Balance the charges by adding subscripts.

Put polyatomics in parenthesis.

WRITING FORMULAS

Write the formula for calcium chloride.

Calcium is Ca+2

Chloride is Cl-1

Ca+2 Cl-1 would have a +1 charge.

Need another Cl-1

Ca+2 Cl2-1

WRITE THE FORMULAS FOR THESE

Lithium sulfide

tin (II) oxide

tin (IV) oxide

Magnesium fluoride

Copper (II) sulfate

Iron (III) phosphide

gallium nitrate

Iron (III) sulfide

WRITE THE FORMULAS FOR THESE

Ammonium chloride

ammonium sulfide

barium nitrate

THINGS TO LOOK FOR

If cations have (), the number is their charge.

If anions end in -ide they are probably off the periodic table (Monoatomic)

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

MOLECULAR COMPOUNDS (COVALENTLY BONDED)

made of just nonmetals

smallest piece is a molecule

can’t be held together because of opposite charges.

can’t use charges to figure out how many of each atom

EASIERMolecular compounds name tells you the number of atoms.

Uses prefixes to tell you the number

PREFIXES

1 mono- 6 hexa-

2 di- 7 hepta-

3 tri- 8 octa-

4 tetra- 9 nona-

5 penta- 10 deca-

PREFIXES

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)

Prefix name Prefix name -ide

NAME THESE

1. N2O

2. NO2

3. Cl2O7

4. CBr4

5. CO2

6. BaCl2

WRITE FORMULAS FOR THESE

1. diphosphorus pentoxide

2. tetraiodide nonoxide

3. sulfur hexaflouride

4. nitrogen trioxide

5. Carbon tetrahydride

6. phosphorus trifluoride

7. aluminum chloride

ACIDS

WRITING NAMES AND FORMULAS

ACIDS

Compounds that give off hydrogen ions when dissolved in water.

Must have H in them.

will always be some H next to an anion.

The anion determines the name.

NAMING ACIDS

If the anion attached to hydrogen is ends in -ide, put the prefix hydro- and change -ide to -ic acid

HCl - hydrogen ion and chloride ion

hydrochloric acid

H2S hydrogen ion and sulfide ion

hydrosulfuric acid

NAMING ACIDS

If the anion has oxygen in it

it ends in -ate of -ite

change the suffix -ate to -ic acid

HNO3 Hydrogen and nitrate ions

Nitric acid

change the suffix -ite to -ous acid

HNO2 Hydrogen and nitrite ions

Nitrous acid

NAME THESE

1. HF

2. H3P

3. H2SO4

4. H2SO3

5. HCN

6. H2CrO4

WRITING FORMULAS

Hydrogen will always be first

name will tell you the anion

make the charges cancel out.

Starts with hydro- no oxygen, -ide

no hydro, -ate comes from -ic, -ite comes from -ous

WRITE FORMULAS FOR THESE

1. hydroiodic acid

2. acetic acid

3. carbonic acid

4. phosphorous acid

5. hydrobromic acid