types of chemical reactions. synthesis decomposition single displacement double displacement...
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Types of Chemical Reactions
Types of Chemical ReactionsSynthesis
Decomposition
Single Displacement
Double Displacement
Combustion
Neutralization
http://www.youtube.com/watch?v=tE4668aarck&feature=player_embedded
Synthesis Reactions• In a synthesis reaction, two simple reactants combine to make a
larger or more complex product• The general pattern for a synthesis reaction is
A + B→ AB
• A and B can be elements or compounds, AB is a compound.
Examples of synthesis reactions:
4 Al(s) + 3 O2(g) → 2 Al2O3(s)
2Mg+O2→2MgO
2Na+Cl2→2NaCl
CaO+ H2O→ Ca(OH)2
Hydrogen chloride + ammonia → ammonium chloride
Decomposition ReactionsDecomposition Reaction- A reaction in which a large or more
complex molecule breaks down to form two (or more) simpler products
-represented by this general equation:
AB→ A + B
AB is a compound, A and B can be elements or compounds
Examples of Decomposition Reactions:
2MgO→2Mg+O2
Ca(OH)2→ CaO+ H2O
H2SO4→SO3+ H2O
2H2O→2H2+ O2
• You must be able to recognize what type of reaction depending on the reactants and product.
• DON’T FORGET THAT SOME ELEMENTS EXIST AS DIATOMIC MOLECULES!!!
• H2, O2, N2, F2, Cl2, Br2, I2
Single Displacement Reactions
Single Displacement Reaction-a reaction in which an element displaces another element in a compound, producing a new compound and a new element
-one element takes the place of (displaces) another element in a compound
-usually metals displace metals, and non metals displace non metals
-represented by this general equation:
A + BC → B + AC
Examples of Single Displacement Reactions:Mg+ 2AgNO3 -> 2Ag + Mg(NO3)2 (silver and magnesium are both metals, magnesium
displaces silver) Br2 + CaI2→CaBr2 + I2
(Bromine displaces Iodine. Bromine and Iodine are both non-metals that have negative ionic charges)
3CuCl2 +2Al→ 2AlCl3 +3Cu(Aluminum, a metal, displaces copper, a metal) Mg +2HCl→ H2+ MgCl2
(Magnesium, a metal, displaces Hydrogen, acting as a metal)
Double Displacement Reactions
Double Displacement Reactions-a reaction that
occurs when elements in different compounds
displace each other or exchange places, producing
2 new compounds
-the METALS (cations) of two compounds exchange
places-a precipitate, a gas or a molecular compound is
usually formed
-represented by this general equation:
AB + CD → AD+ CB
Examples of Double Displacement Reactions:
2KI + Pb(NO3)2→PbI2+ 2KNO3
FeS + 2HCl→ H2S + FeCl2
Pb (NO3)2 + K2CrO4 → PbCrO4 + 2KNO3
COMBUSTION• Combustion reactions always
involve molecular oxygen O2. Anytime anything burns (in the usual sense), it is a combustion reaction.
• Combustion reactions almost always give off heat. For example when wood burns, it must do so in the presence of O2 and a lot of heat is produced:
• For example consider the combustion of methanol (rubbing alcohol):
• Of course, not all combustion reactions release CO2 and water, e.g., the combustion of magnesium metal:
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