How can we tell if a reaction takes

place?

How can we tell if a reaction takes place?

There are four clues:

1. _______________

2. _______________

3. _______________

4. _______________

How can we tell if a reaction takes place?

There are four clues:

1. Heat or light is given off

2. _______________

3. _______________

4. _______________

How can we tell if a reaction takes place?

There are four clues:

1. Heat or light is given off

2. A gas is produced

3. _______________

4. _______________

How can we tell if a reaction takes place?

There are four clues:

1. Heat or light is given off

2. A gas is produced

3. A precipitate forms

4. _______________

How can we tell if a reaction takes place?

There are four clues:

1. Heat or light is given off

2. A gas is produced

3. A precipitate forms

4. A change in color occurs

Type of Reactions

Chemical reactions are classified into six general types

Synthesis

Synthesis

Two or more elements or simple compounds combine to form (synthesize) one product

A + B AB

2Mg + O2 2MgO

2Na + Cl2 2NaCl

SO3 + H2O H2SO4

Type of Reactions

Chemical reactions are classified into six general types

Synthesis

Decomposition

Decomposition

One substance is broken down (split) into two or more simpler substances.

AB A + B

2HgO 2Hg + O2

2KClO3 2KCl + 3 O2

Types of Reactions

Classify the following reactions as

1) synthesis or 2) decomposition:

___A. H2 + Br2 2HBr

___B. Al2(CO3)3 Al2O3 + 3CO2

___C. 4 Al + 3C Al4C3

Solution

Classify the following reactions as

1) combination or 2) decomposition:

_1_A. H2 + Br2 2HBr

_2_B. Al2(CO3)3 Al2O3 + 3CO2

_1_C. 4 Al + 3C Al4C3

Special Decomposition Reactions

Metallic Carbonates decompose to form metallic oxides and carbon dioxide

CaCO3 CaO + CO2

Al2(CO3)3 Al2O3 + 3 CO2

Special Decomposition Reactions

Metallic Hydrogen Carbonates (bicarbonates) decompose to form metallic oxides, carbon dioxide and water2NaHCO3 Na2O + H2O + 2CO2

2 Al(HCO3)3 Al2O3 + 3 H2O + 6 CO2

Special Decomposition Reactions

Metallic Chlorates decompose into metallic chlorides and oxygen

2KClO3 2KCl + 3O2

Ni(ClO3)4 NiCl4 + 6O2

Type of Reactions

Chemical reactions are classified into six general types

Synthesis

Decomposition

Single Replacement

Single Replacement

One element takes the place of an element in a reacting compound.

A + BC AB + C

Zn + 2HCl ZnCl2 + H2

Fe + CuSO4 FeSO4 + Cu

2KI + Cl2 2KCl + I2

Type of Reactions

Chemical reactions are classified into six general types

Synthesis

Decomposition

Single Replacement

Double Replacement

Double Replacement

Two elements in reactants take the place of each other

AB + CD AD + CB

AgNO3 + NaCl AgCl + NaNO3

ZnS + 2HCl ZnCl2 + H2S

Classifying Reactions

Classify the following reactions as

1) single replacement

2) double replacement

__A. 2Al + 3H2SO4 Al2(SO4)3 + 3H2

__B. Na2SO4 + 2AgNO3 Ag2SO4 + 2NaNO3

__C. 3C + Fe2O3 2Fe + 3CO

Solution

Classify the following reactions as

1) single replacement

2) double replacement

1_A. 2Al + 3H2SO4 Al2(SO4)3 + 3H2

2_B. Na2SO4 + 2AgNO3 Ag2SO4 + 2NaNO3

1_C. 3C + Fe2O3 2Fe + 3CO

Type of Reactions

Chemical reactions are classified into six general types

Synthesis

Decomposition

Single Replacement

Double Replacement

Combustion

Combustion

A reaction in which a compound (most

often carbon) reacts with oxygen

C + O2 CO2

CH4 + 2O2 CO2 + 2H2O

C3H8 + 5O2 3CO2 + 4H2O

C6H12O6 + 6O2 6CO2 + 6H2O

Type of Reactions

Chemical reactions are classified into six general types

Synthesis

Decomposition

Single Replacement

Double Replacement

Combustion

Neutralization

Neutralization

A reaction in which a base (contains

OH-) reacts with an acid (contains H+)

to produce a salt and water

NaOH + HCl NaCl + H2O

H2SO4 + 2NaOH Na2SO4 + 2H2O

Balancing Equations

Balance the combustion equation

___C5H12 + ___O2 ___CO2 + ___H2O

Solution

Balance the combustion equation

1 C5H12 + 8 O2 5 CO2 + 6 H2O