Starter S-105
1. How many grams of copper (II) chloride
are in 3.83 x 1021 formula units?
Chapter 11
Chemical Reactions
Chapter 11
11.1 Describing Chemical Reactions
11.1 Describing Chemical Reactions
Writing Chemical Reactions
Word Equations – gives the names of
compounds and elements in the equation
reactants  products
Reactants – compounds and elements
before the reaction
Products – compounds and elements after
the reaction
11.1 Describing Chemical Reactions
Different compounds, or elements are
separated by a plus sign
Copper + Oxygen  Copper (II) Oxide
These are often converted from descriptions
of the reaction
11.1 Describing Chemical Reactions
When antiseptic hydrogen peroxide is put in
an open cut bubbles of oxygen form
rapidly. Water is also produced.
Reaction – reactants
hydrogen peroxide
11.1 Describing Chemical Reactions
When antiseptic hydrogen peroxide in an
open cut bubbles of oxygen from rapidly.
Water is also produced.
Reaction – products
hydrogen peroxide
11.1 Describing Chemical Reactions
When antiseptic hydrogen peroxide in an
open cut bubbles of oxygen from rapidly.
Water is also produced.
Reaction – products
hydrogen peroxide  oxygen + water
11.1 Describing Chemical Reactions
When a stove burner is lit, methane gas reacts
with oxygen to form carbon dioxide and water.
Reaction – reactants
methane gas + oxygen
11.1 Describing Chemical Reactions
When a stove burner is lit, methane gas reacts
with oxygen to carbon dioxide and water.
Reaction – products
methane gas + oxygen
11.1 Describing Chemical Reactions
When a stove burner is lit, methane gas reacts
with oxygen to carbon dioxide and water.
Reaction – products
methane gas + oxygen  carbon dioxide + water
11.1 Describing Chemical Reactions
Chemical Equations – replace the names of
compounds and elements with the
chemical formula
hydrogen peroxide  oxygen + water
H 2 O 2  O 2 + H 2O
Remember diatomic elements
11.1 Describing Chemical Reactions
methane gas + oxygen  carbon dioxide + water
CH4 + O2  CO2 + H2O
11.1 Describing Chemical Reactions
Usually the state of
each compound
or element is
given beside the
formula
Solid
(s)
Liquid
(l)
Gas
(g)
Aqueous
(aq)
CH4(g)+ O2(g)  CO2(g) + H2O(g)
Starter S-106
When solutions of potassium iodide and
lead (II) nitrate are mixed in a beaker, a
brilliant yellow solid is formed. This solid
when analyzed turns out to be lead (II)
iodide. Further analysis shows that
potassium nitrate is now dissolved in the
water.
A. Write the word equation.
B. Write the chemical equation
11.1 Describing Chemical Reactions
Balancing Chemical Equations – both sides
of a chemical equation have the same
number of each atom
Mass is conserved
Balancing Demo
11.1 Describing Chemical Reactions
Example
Al +
O2  Al2O3
1. Write elements on each side and how
many of each are present
11.1 Describing Chemical Reactions
Example
Al +
Al – 1
O–2
O2  Al2O3
Al – 2
O–3
2. Add one element at a time to the side that
doesn’t have enough
11.1 Describing Chemical Reactions
Al
Al +
Al – 2
O–2
O2  Al2O3
Al – 2
O–3
11.1 Describing Chemical Reactions
Al
Al +
Al – 2
O–4
O2
O2  Al2O3
Al – 2
O–3
11.1 Describing Chemical Reactions
Al
Al +
Al – 2
O–4
O2
Al2O3
O2  Al2O3
Al – 4
O–6
11.1 Describing Chemical Reactions
Al,Al,Al O2
Al2O3
Al +
O2  Al2O3
Al – 4
O–4
Al – 4
O–6
11.1 Describing Chemical Reactions
Al,Al,Al O2,O2 Al2O3
Al +
O2  Al2O3
Al – 4
Al – 4
O–6
O–6
Balanced
3. Count the number of each compound or
element – write a coefficient for each
11.1 Describing Chemical Reactions
4Al + 3O2  2Al2O3
11.1 Describing Chemical Reactions
Balance the following equations
A. Cu + AgNO3  Cu(NO3)2 + Ag
11.1 Describing Chemical Reactions
Balance the following equations
A. Cu + 2AgNO3  Cu(NO3)2 + 2Ag
B. FeCl3 + NaOH  Fe(OH)3 + NaCl
11.1 Describing Chemical Reactions
Balance the following equations
A. Cu + 2AgNO3  Cu(NO3)2 + 2Ag
B. FeCl3 + 3NaOH  Fe(OH)3 + 3NaCl
C. CS2 + Cl2  CCl4 + S2Cl2
11.1 Describing Chemical Reactions
Balance the following equations
A.
B.
C.
D.
Cu + 2AgNO3  Cu(NO3)2 + 2Ag
FeCl3 + 3NaOH  Fe(OH)3 + 3NaCl
CS2 + 3Cl2  CCl4 + S2Cl2
AgNO3 + H2S  Ag2S + HNO3
11.1 Describing Chemical Reactions
Balance the following equations
A.
B.
C.
D.
E.
Cu + 2AgNO3  Cu(NO3)2 + 2Ag
FeCl3 + 3NaOH  Fe(OH)3 + 3NaCl
CS2 + 3Cl2  CCl4 + S2Cl2
2AgNO3 + H2S  Ag2S + 2HNO3
Zn(OH)2 + H3PO4  Zn3(PO4)2 + H2O
11.1 Describing Chemical Reactions
Balance the following equations
A.
B.
C.
D.
E.
F.
Cu + 2AgNO3  Cu(NO3)2 + 2Ag
FeCl3 + 3NaOH  Fe(OH)3 + 3NaCl
CS2 + 3Cl2  CCl4 + S2Cl2
2AgNO3 + H2S  Ag2S + 2HNO3
3Zn(OH)2 + 2H3PO4  Zn3(PO4)2 + 6H2O
Fe2O3 + H2  Fe + H2O
11.1 Describing Chemical Reactions
Balance the following equations
A.
B.
C.
D.
E.
F.
Cu + 2AgNO3  Cu(NO3)2 + 2Ag
FeCl3 + 3NaOH  Fe(OH)3 + 3NaCl
CS2 + 3Cl2  CCl4 + S2Cl2
2AgNO3 + H2S  Ag2S + 2HNO3
3Zn(OH)2 + 2H3PO4  Zn3(PO4)2 + 6H2O
Fe2O3 + 3H2  2Fe + 3H2O
Starter S-107
1. Balance
C6H6 + O2  CO2 + H2O
CH3CH2OH + O2  CO2 + H2O
Chapter 11
11.2 Types of Chemical Reactions
11.2
Reactions
11.2Type
TypesofofChemical
Chemical Reactions
You will need to know and predict the
product for 6 types of chemical
reactions
1. Synthesis
Form
Example
A  B  AB
Synthesis
2 H 2 ( g )  O2 ( g )  2 H 2O( g )
11.2
Reactions
11.2Type
TypesofofChemical
Chemical Reactions
2. Decomposition
Form
AB  A  B
Example
2H 2O( g ) 
 2H 2( g )  O2( g )
electricity
Decomposition
11.2
Reactions
11.2Type
TypesofofChemical
Chemical Reactions
3. Single Replacement Reaction
Form
A  BC  B  AC
Example
Zn( s )  Cu( NO3 ) 2( aq)  Cu( s )  Zn( NO3 ) 2( aq)
For metals, the reactions occurs if
the metal is more reactive than the
the one in the compound
Single
11.2
Reactions
11.2Type
TypesofofChemical
Chemical Reactions
4. Double Replacement Reaction
Form
AB  CD  AD  CB
Example
Na2 S( aq)  Cd ( NO3 )2( aq)  CdS( s )  2 NaNO3( aq)
Double
11.2
Reactions
11.2Type
TypesofofChemical
Chemical Reactions
5. Combustion Reaction
Form
AB  O2  AO  BO
Example
2C8 H18(l )  25O2( g )  16CO2( g )  18H 2O
Combustion
11.2
Reactions
11.2Type
TypesofofChemical
Chemical Reactions
6. Acid/Base Neutralization Reaction
Form
HA  BOH  AB  H 2O
Example
HCl( aq)  NaOH ( aq)  NaCl( aq)  H 2O(l )
The substance AB is called a
Chemical Salt
Acid Base
11.2
Reactions
11.2Type
TypesofofChemical
Chemical Reactions
Reactions are predicted based on recognizing
forms.
Starter S-110
What type of reaction is this?
CaCl2 + Pb(NO3)2 
Write the complete balanced equation
11.2
Reactions
11.2Type
TypesofofChemical
Chemical Reactions
Reaction
AgNO3 + NaCl 
Type:
Double Replacement
Products:
AgNO3 + NaCl  AgCl + NaNO3
Balanced:
AgNO3 + NaCl  AgCl + NaNO3
11.2
Reactions
11.2Type
TypesofofChemical
Chemical Reactions
Reaction
Pb + AgNO3 
Type:
Single Replacement
Products:
Pb + AgNO3  Ag + Pb(NO3)2
Balanced:
Pb + 2AgNO3  2Ag + Pb(NO3)2
11.2
Reactions
11.2Type
TypesofofChemical
Chemical Reactions
Reaction
FeCl3 + KOH 
Type:
Double Replacement
Products:
FeCl3 + KOH  Fe(OH)3 + KCl
Balanced:
FeCl3 + 3KOH  Fe(OH)3 + 3KCl
11.2
Reactions
11.2Type
TypesofofChemical
Chemical Reactions
Reaction
NaOH + H2SO4 
Type:
Acid Base Neutralization
Products:
NaOH + H2SO4  Na2SO4 + H2O
Balanced:
2NaOH + H2SO4  Na2SO4 + 2H2O
11.2
Reactions
11.2Type
TypesofofChemical
Chemical Reactions
Reaction
C2H8 + O2 
Type:
Combustion
Products:
C2H8 + O2  CO2 + H2O
Balanced:
C2H8 + 4O2  2CO2 + 4H2O
11.2
Reactions
11.2Type
TypesofofChemical
Chemical Reactions
Reaction
NH3 
Type:
Decomposition
Products:
NH3  N2 + H2
Balanced:
2NH3  N2 + 3H2
11.2
Reactions
11.2Type
TypesofofChemical
Chemical Reactions
Reaction
Bi(NO3)3 + H2S 
Type:
Double Replacement
Products:
Bi(NO3)3 + H2S  Bi2S3 + HNO3
Balanced:
2Bi(NO3)3 + 3H2S  Bi2S3 + 6HNO3
Starter S-111
What type of reaction is
Fe + CuCl2 
Write and balance the reaction
Chapter 11
11.3 Reactions in Aqueous Solutions
11.2
Type of Chemical
Reactions
11.3 Reactions
in Aqueous
Solution
Many reactions take place in water –
aqueous
For example, the reaction of Silver Nitrate
and Sodium Chloride
AgNO3( aq)  NaCl( aq)  AgCl( s )  NaNO3( aq)
But in a solution, most ionic compounds have
dissociated to form ions
11.2
Type of Chemical
Reactions
11.3 Reactions
in Aqueous
Solution
That is they are really in this form
Ag

( aq)

3( aq)
 NO

( aq)
 Na

( aq)
 Cl

( aq)
 AgCl( s )  Na

3( aq)
 NO
This is called the Complete Ionic Equation
AgNO–3(the
NaCl
AgCl(into
NaNOonly
Notice
solid
is( aq
not
broken
aq ) 
) 
s )  ions,
3( aq )
what is in solution
11.2
Type of Chemical
Reactions
11.3 Reactions
in Aqueous
Solution
Look carefully at the equation
Ag

( aq)

3( aq)
 NO

( aq)
 Na

( aq)
 Cl

( aq)
 AgCl( s )  Na

3( aq)
 NO
There are Na+ and NO3- ions that stay the
same
These are called Spectator Ions
A Net Ionic Equation shows only ions that
actually do something in a reaction
11.2
Type of Chemical
Reactions
11.3 Reactions
in Aqueous
Solution
Net Ionic Equation
Ag

( aq)

3( aq)
 NO

( aq)
 Na
Ag

( aq)
 Cl

( aq)
 AgCl( s )  Na

3( aq)
 NO
Try this one

( aq()s )

3( aq
3((aq
)aq))
2
( aq) 3 2( aq)

3( aq)
Pb( s ) Pb
 2( sAg
Pb
2 AgNO
22NO
Ag 2 2
Ag
Ag
Pb
Pb
( NO ) 2 NO
) 
( s )( s
) 
11.2
Type of Chemical
Reactions
11.3 Reactions
in Aqueous
Solution
Practice
Equation
Na3 PO4( aq)  FeCl3( aq)  3NaCl( aq)  FePO4( s )
Compete Ionic Equations
3Na(aq)  PO4(3aq)  Fe(aq3 )  3Cl(aq)  3Na(aq)  3Cl(aq)  FePO4( s )
Net Ionic Equation
PO4(3aq)  Fe(aq3 )  FePO4( s )
Starter S-112
Write the complete ionic and net ionic equations
for
Fe(NO3)3(aq) + 3NaOH(aq)  Fe(OH)3(s) + 3NaNO3(aq)
Complete Ionic
Fe+3(aq)+3NO3-(aq) + 3Na+(aq)+3OH-(aq) Fe(OH)3(s)+ 3Na+(aq)+3NO3-(aq)
Net Ionic
Fe+3(aq)+3OH-(aq) Fe(OH)3(s)
11.2
Type of Chemical
Reactions
11.3 Reactions
in Aqueous
Solution
Precipitate – separates from a solution as a
solid
Predicted using a solubility
Chart
chart
In the reaction
AgNO3( aq)  NaCl( aq)  AgCl  NaNO3
Is either product a solid?
11.2
Type of Chemical
Reactions
11.3 Reactions
in Aqueous
Solution
AgNO3( aq)  NaCl( aq)  AgCl  NaNO3
AgCl – insoluble
NaNO3
11.2
Type of Chemical
Reactions
11.3 Reactions
in Aqueous
Solution
AgNO3( aq)  NaCl( aq)  AgCl  NaNO3
AgCl – insoluble - solid
NaNO3
11.2
Type of Chemical
Reactions
11.3 Reactions
in Aqueous
Solution
AgNO3( aq)  NaCl( aq)  AgCl  NaNO3
AgCl – insoluble - solid
NaNO3 – soluble
11.2
Type of Chemical
Reactions
11.3 Reactions
in Aqueous
Solution
AgNO3( aq)  NaCl( aq)  AgCl  NaNO3
AgCl – insoluble - solid
NaNO3 – soluble - aqueous