Chemical Formulas

Copy the text colored RED or Purple throughout the PPT. Also complete the TABLES

You have lists of:Common polyatomic ionsMultivalent metalsCovalent prefixes

Use your periodic table to determine the charges of common elements when they form ions

Reminders from Naming Chemicals

Binary Ionic compounds

Definitions- Review

Binary Ionic Compound- compound containing two elements—one metal and one non-metal

+Cation

+Cation

-Anion

-Anion Ionic Compound

Ionic bond- bond formed by attraction between + and - ions

Metals & Non-Metals

Ionic Bonds are between metals & non-metals

H He

Li Be B C N O F Ne

Na Mg Al Si P S Cl Ar

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe

Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn

Fr Ra Lr Rf Db Sg Bh Hs Mt Uun Uuu Uub Uut

Metals Metalloids Non-metals

These compounds:End in “-ide” (except “hydroxide and cyanide”)Do NOT contain covalent prefixes

To write these formulas:Write the symbol & charge of the first element (the metal,

cation)Write the symbol & charge of the second element (the

non-metal, anion)Add more of the cations and/or anions to have a neutral

compoundUse subscripts to show how many of each type of ion is

there.

Identifying & Naming Binary Ionic

Name Cation Anion Criss Cross Formula

Sodium Chloride

Calcium Bromide

Cesium Chloride

Aluminum Sulfide

Potassium Oxide

Calcium Sulfide

Lithium NItride

21

Na+1 Cl-1 None NaCl

Ca+2 Br-1 Ca+2 Br-1 CaBr2

Example #1

Sodium chloride

Example #1

Sodium chloride

Cation

Anion

Na+1

Cl-1

NaCl

Example #1

Sodium chloride

Cation

Anion

Na+1

Cl-1

NaCl

Na+1Cl-1

The +1 and -1 cancel each other out

The compound is neutral…no subscripts are needed.

Example #2

Calcium bromide

Example #2

Calcium bromide

Cation

Anion

Ca+2

Br-1

Example #2

Calcium bromide

Cation

Anion

Ca+2

Br-1

CaBr2

Ca+2Br-1

Criss Cross the charges down

Ca+2 Br-1

The subscript “1” is dropped because its redundant. The subscript “2” is used to show that 2 anions are needed.

Ca1Br2

1 2

Example #3

Aluminum Sulfide

Example #3

Aluminum Sulfide

Cation

Anion

Al+3

S-2

Example #2

Aluminum Sulfide

Cation

Anion

Al+3

S-2

Al2S3

Al+3 S-2

Criss Cross the charges down

The subscript “2” is used to show that 2 cations are needed. The subscript “3” is used to show that 3 anions are needed.

Al2S3

2 3Al+3 S-2

Let’s Practice

Example:Write the following chemical formulas

Cesium chloride

Potassium oxide

Calcium sulfide

Lithium nitride

Let’s Practice

CsCl

K2O

CaS

Li3N

Example:Write the following chemical formulas

Cesium chloride

Potassium oxide

Calcium sulfide

Lithium nitride

Polyatomic Ionic Compounds

Definition-Review

Polyatomic Ion- more than one atom that together have a charge

+Cation

+Cation

Polyatomic Ionic Compound- compound containing at least one polyatomic ion

-Polyatomic

Anion

Polyatomic IonicCompound

These compounds:Do not end with “-ide” (except hydroxide & cyanide)Do not use covalent prefixes

To write these formulas:Write the symbol & charge of the cation & anionAdd additional cations or anions to have a neutral

compoundUse subscripts to show the number of ions

When using subscripts with a polyatomic ion, you must put the polyatomic ion in parenthesis.

Identifying & Naming Polyatomic Ionic

Name Cation Anion Criss Cross Formula

Sodium Carbonate

Magnesium Nitrate

Lithium Iodate

Sodium Nitrate

Calcium Chlorate

Potassium Sulfite

Calcium Hydroxide

Example #4

Sodium carbonate

Example #4

Sodium carbonate

Cation

PolyatomicAnion

Na+1

CO3-2

Example #4

Sodium carbonate

Cation

PolyatomicAnion

Na+1

CO3-2

Na2CO3

Na+CO32-

Criss Cross the charges down

Na+ CO32-

The subscript “2” is used to show that 2 cations are needed.

Na2CO3

2 1

Example #5

Magnesium nitrate

Example #5

Magnesium nitrate

Cation

PolyatomicAnion

Mg+2

NO3-1

Example #5

Magnesium nitrate

Cation

PolyatomicAnion

Mg+2

NO3-1

Mg(NO3)2 Use parenthesis when adding subscripts to polyatomic ions

Mg+2NO3-1

Criss Cross the charges down

Mg+2 NO3-1

The subscript “2” is used to show that 2 anions are needed.

Mg(NO3)2

21

Let’s Practice

Example:Write the following chemical formulas

Lithium Iodate

Sodium nitrate

Calcium chlorate

Potassium sulfite

Calcium hydroxide

Let’s Practice

LiIO3

NaNO3

Ca(ClO3)2

K2SO3

Ca(OH)2

Example:Write the following chemical formulas

Lithium iodate

Sodium nitrate

Calcium chlorate

Potassium sulfite

Calcium hydroxide

Multivalent Metals

Definition-Review

Multivalent Metal- metal that has more than one possibility for cationic charge

These compounds:Will have roman numerals

To write these formulas:Same as binary ionic or polyatomic ionic.The roman numerals tell the charge of the

metal (cation)

Identifying & Naming Multivalent Metals

Name Cation Anion Criss Cross Formula

Iron (III) Oxide

Copper (II) Nitrate

Iron (II) Nitrate

Copper (I) Chloride

Lead (IV) Hydroxide

Tin (II) Oxide

Example #5

Iron (III) oxide

Example #5

Iron (III) oxide

Cation

Anion

Fe+3

O-2

Example #6

Iron (III) oxide

Cation

Anion

Fe+3

O-2

Fe2O3

Fe+3O2-

Criss cross the charges

Fe+3 O2-

The subscript “2” and “3” are used to show the numbers of atoms needed.

Fe2O3

32

Example #7

Copper (II) nitrate

Example #7

Copper (II) nitrate

Cation

PolyatomicAnion

Cu+2

NO3-1

Example #7

Copper (II) nitrate

Cation

PolyatomicAnion

Cu+2

NO3-1

Cu(NO3)2

Cu+2NO3-1

Criss cross the charges

Cu+2 NO3-1

Use parenthesis when adding subscripts to a polyatomic ion

Cu(NO3)2

1 2

Let’s Practice

Example:Write the following chemical formulas

Iron (II) nitrate

Copper (I) chloride

Lead (IV) hydroxide

Tin (II) oxide

Let’s Practice

Fe(NO3)2

CuCl

Pb(OH)4

SnO

Example:Write the following chemical formulas

Iron (II) nitrate

Copper (I) chloride

Lead (IV) hydroxide

Tin (II) oxide

Binary Covalent Compounds

Definition-Review

Binary Covalent Compound compound made from two non-metals that share electrons

Nonmetal

Nonmetal

Nonmetal

Nonmetal Covalent compound

Covalent bond atoms share electrons

These compounds:Use covalent prefixes

To write these formulas:Write the symbols of the first and second

elementUse the covalent prefixes (assume the first

element is “1” if there’s no prefix) as the subscripts to show number of atoms.

Identifying & Naming Binary Covalent

Atoms do not form charges when bonding covalently…you DO NOT need to worry about charges with this type!

Name Prefix First Element

Prefix Second Element

Formula

Dinitrogen Tetraoxide

Di- = 2 Nitrogen = N Tetra- = 4 Oxide = O N2O4

Silicon dioxide

Carbon monoxide

Nitrogen dioxide

Diphosphorus pentaoxide

Carbon Tetrachloride

Example #7

Dinitrogen Tetraoxide

Example #7

Dinitrogen Tetraoxide

N

O

“Di-” = 2

“Tetra-” = 4

N2O4

Example #8

Silicon dioxide

Example #8

Silicon dioxide

Si

O

“Mono-” is not written for the first element

“Di-” = 2

SiO2

CAUTION!!!

bi-di-

Stands for “2” in covalent compounds

Means there’s a hydrogen in the polyatomic anion

“di” and “bi” do not mean the same thing!

Carbon dioxide = CO2

Sodium biphosphate = Na2HPO4

Let’s Practice

Example:Write the following chemical formulas

Carbon monoxide

Nitrogen dioxide

Diphosphorus pentaoxide

Carbon tetrachloride

Let’s Practice

CO

NO2

P2O5

CCl4

Example:Write the following chemical formulas

Carbon monoxide

Nitrogen dioxide

Diphosphorus pentaoxide

Carbon tetrachloride

Nomenclature Summary

Mixed Practice

Example:Write the following chemical formulas

Magnesium hydroxide

Copper (II) nitrate

Iron (III) oxide

Nitrogen dioxide

Sodium bicarbonate

Mixed Practice

Mg(OH)2

Cu(NO3)2

Fe2O3

NO2

NaHCO3

Example:Write the following chemical formulas

Magnesium hydroxide

Copper (II) nitrate

Iron (III) oxide

Nitrogen dioxide

Sodium bicarbonate