Transcript FIVE BASIC WAYS TO CLASSIFY CHEMICAL REACTIONS:

CLASSIFYING
CHEMICAL REACTIONS
FIVE BASIC WAYS TO CLASSIFY
CHEMICAL REACTIONS:
1.
2.
3.
4.
5.
Synthesis
Decomposition
Single-Replacement
Double-Replacement
Combustion
Synthesis Reactions:
• Generic Reaction
• X + Y-->XY
• Definition-In this
equation, X and Y can
be compounds or
elements. The result
XY is a compound.
2 Reactants and 1 Product
Analogy- Like a marriage
Examples of Real
Synthesis Reactions:
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2Ba + O2 -->2BaO
4Cu + O2 -->2Cu2O
2Cu + O2 -->2CuO
2H2 + O2 -->2H2O
C + O2 -->CO2
2Na + Cl2 -->2NaCl 2
Decomposition Reactions:
• In a decomposition
reaction, an compound is
broken down into two
simpler substances. The
generic formula of a
decomposition reaction
is:
• XY --> X + Y
• Decomposition reactions
are the opposite of
synthesis reactions.
Analogy-Like divorce
1 Reactant and 2 Products
Examples of Real
Decomposition Reactions:
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2HgO --> 2Hg + O2
2H2O --> 2H2 + O2
CaCO3 --> CaO + CO2
Cu(OH)2 --> CuO + H2O
2KClO3 --> 2KCl + 3O2
H2SO4 --> SO3 + H2O
Single Replacement Reactions:
• In this type of
reaction, one element
replaces a similar
element in a
Aggressive metal wins
compound.
• A + XY --> AY + X 1 free element + compound 
• In this equation, A, X, compound + 1 free element
and Y are the
elements and XY, AY, Like finding a new girl friend
and XA are the
compounds.
Li
Rb
K
Ca
Na
Mg
Al
Mn
Zn
Fe
Ni
Sn
Pb
H
Cu
Ag
Pt
Au
Metal Reactivity Chart
Most aggressive metal (woman) wins out
Examples of Single Replacement
Reactions:
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2Al + 3Fe(NO3)2  3Fe + 2Al(NO3)3
Zn + CuCl2 
Mg + Pb(NO3)2 
Fe + Na3PO4 
2K + ZnCl2 
Examples of Real
Single Replacement Reactions:
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2Al + 3Fe(NO3)2  3Fe + 2Al(NO3)3
Zn + CuCl2  Cu + ZnCl2
Mg + Pb(NO3)2  Pb + Mg (NO3)2
Fe + Na3PO4  N.R.
2K + ZnCl2  2 KCl + Zn
Cl2 + 2KBr  2KCl + Br2
Double-Replacement Reactions:
• In a double-replacement
reaction, the two
compounds exchange
places in a solution to
form two new
compounds. The general
equation of a doublereplacement reaction is:
• AB + XY --> AY + XB Like switching partners in
2 compounds  2 compounds square dancing
Examples of Real
Double-Replacement Reactions:
• Pb(NO3)2 + 2KI --> PbI2 + 2KNO3
• FeS + 2HCl --> H2S + FeCl2
• HCl + NaOH --> NaCl + H2O
“lets take turns dancing with these two beautiful ladies”
Combustion Reactions:
• When a substance
combines with
oxygen releasing a
large amount of
energy in the form of
light and heat, it is a
combustion reaction.
Oxygen is needed to
Burn things.
Generic
C + O2  CO2 + heat
Examples of Real
Combustion Reactions:
• examples of combustion reactions
• C3H8 + 5O2 --> 3CO2 + 4H2O + heat
• 2CH4 + 4O2  2CO2 + 4H2O + heat
FIVE BASIC WAYS TO CLASSIFY
CHEMICAL REACTIONS:
1.
2.
3.
4.
5.
Synthesis 2 reactants1 product (like marriage)
Decomposition 1 reactant 2 products(like divorce)
Single-Replacement(most aggressive element wins)
Double-Replacement (switch partners)
Combustion=Burning (need oxygen to burn things)