Types of Chemical

Reactions

Synthesis Reactions

A + B AB

The word “synthesize” means

to produce.

How to identify:

2 elements one product.

Synthesis Reaction Ex.

• 4Fe + 3O2 2Fe

2O

3

• Iron + Oxygen Iron (III) Oxide

Decomposition Reactions

AB A + B

How to identify: they

always have only one

reactant.

Decomposition Rxn. Ex.

• H2CO

3 CO

2+ H

2O

• Carbonic acid Carbon dioxide + Water

Single Replacement

A + BC AC + B

A single metal replaces

another one in a

compound.

Double Replacement

AB + CD AD + CB

The metals in two

compounds switch places.

(2 compounds 2 new

compounds)

Combustion

Organic cmpd. + O2

CO2

+ H2O

An organic compound

is any compound

containing C, H, and

sometimes O.

Predicting

Products of

Reactions

Synthesis

Two elements

Write the formula correctly

by balancing charges.

Synthesis cont...

Nonmetal oxide + water

Acid

Combine atoms from both

reactants. Start acid

formula with H.

Decomposition

Binary Compound

Break into elements.

Decomposition cont...

Metal Carbonate Metal

oxide + CO2

Single Replacement

Metal + Compound(aq)

Use “activity series”

If the lone metal is higher than

the one in the compound there

will be a reaction.

If not, write “N.R.” in the

products.

Ex.

2Al(s)

+ 3Pb(NO3)2(aq)

3Pb(s)

+

2Al(NO3)3(aq)

Al is more reactive (“fun”) and

kicks Pb out of the “friendship”

Double Replacement

Compound(aq)

+ Compound(aq)

Use the Solubility Table from

your book. If both products

are SOLUBLE, write “N.R.” in

the products.

Combustion

Organic + O2

CO2

+ H2O

Completely perfect combustion,

but not reality.

Reactions in

Aqueous Solution

Ions in Solution

When ionic compounds dissolve in

water they break apart:

“NaCl(aq)

” means Na+

(aq) + Cl

-

(aq)

“CaCl2(aq)

” means Ca+2

(aq)+ 2Cl

-

(aq)

Ionic Equations

In a “complete ionic equation” you split the

aqueous compounds into their ions:

NaCl(aq)

+ AgNO3(aq)

NaNO3(aq)

+ AgCl(s)

Becomes

Na+

(aq)+ Cl

-

(aq)+ Ag

+

(aq)+ NO

3

-

(aq) Na

+

(aq)+ NO

3

-

(aq)+

AgCl(s)

Ionic Equations

Some of the ions don’t change

from one side to the other

(Na+ and NO

3

-). They are

“spectator ions”.

Net Ionic Equations

“Net” means

“after adjustments and deductions”.

Writing the net ionic equation you

leave the spectator ions out.

Ag+

(aq)+ Cl

-

(aq) AgCl

(s)

Examples

Balance these, then write the

complete ionic equation:

Pb(ClO4)2(aq)

+ NaI(aq) PbI

2(s)+

NaClO4(aq)

Zn(s)

+ HCl(aq)

ZnCl2(aq)

+ H2(g)

Examples

Now give the net ionic equation

of the two reactions.

Pb+2

(aq)+ 2I

-

(aq) PbI

2(s)

Zn(s)

+ 2H+

(aq) Zn

+2

(aq)+ H

2(g)

Keep in Mind

When you have the SAME

coefficient for ALL of the

reactants AND products, reduce

them to ONE.