Download - Chemical Reaction Types
Chemical Reaction Types
Chemical reaction types
• We will study these five general types of reactions:
• synthesis • decomposition• single displacement• double displacement• combustion.
Once you know these reaction types, you will be able to look at the reactants of a reaction and
predict what products will be formed.
Synthesis: two simple substances combine to form a more complex one.
The general form is: element + element compound
2Na + Cl2→ 2NaCl
4Fe + 3O2 → 2Fe2O3
SYNTHESIS
More Examples:
2H2 + O2 2H2O
4Al + 3O2 2Al2O3
Ca + Cl2 CaCl2
Decomposition: a complex substance breaks down into two simple substances.
The general form is: Compound element + element
2H2O → 2H2 + O2
H2CO3 → H2O + CO2
DECOMPOSITION
More Examples:
2HgO 2Hg + O2
2KClO3 2KCl+ 3O2
The general form is:
element + compound compound + element
• Zn + 2HCl ZnCl2 + H2
• 2Na + 2H2O 2NaOH + H2
Single displacement: a single element replaces an element in a compound.
SINGLE REPLACEMENT
More Examples:
Zn + Cu(NO3)2 Cu + Zn(NO3)2
Cu + 2 AgNO3 2Ag + Cu(NO3)2
Mg + 2HCl H2 + MgCl2
The general form is:
compound + compound compound + compound
• MgCO3 + 2HCl MgCl2 + H2CO3
• 2KCl + Pb(NO3)2 2KNO3 + PbCl2
Double displacement: different atoms in two different compounds replace each other.
DOUBLE REPLACEMENTMore Examples:
AgNO3 + NaCl AgCl + NaNO3
NaOH + HCl NaCl + H2O
Ba(NO3)2 + Na2SO4 BaSO4 + 2NaNO3
The general form is:
hydrocarbon + oxygen carbon dioxide + water
• CH4 + 2O2 CO2 + 2H2O
• C7H16 + 11O2 7CO2 + 8H2O
Combustion: a hydrocarbon (molecule containing only carbon and hydrogen atoms) reacts with oxygen. The products of combustion are always carbon dioxide and water.
COMPLETE COMBUSTION
Example:
2CH4 + 4O2 2CO2 + 4 H2O