Answer:
The Four Major Types of Reactions
Name General Reaction Pattern
Combination or synthesis A + B ----> AB
Decomposition AB ----> A + B
Substitution or Single Replacement A + BC ----> B + AC
Metathesis or Double Displacement AB + CD ----> AD + CB
Combination or Synthesis Reactions Two or more reactants unite to form a single product.
S + O2 ---------> SO2
sulphur oxygen sulphur dioxide
2 S + 3 O2 ---------> 2 SO3
sulphur oxygen sulphur trioxide
2 Fe + O2 ---------> 2 FeO
iron oxygen iron (II) oxide
Decomposition Reactions A single reactant is decomposed or broken down into two or more
products.
CaCO3 ----------> CaO + CO2
calcium carbonate calcium oxide carbon dioxide
2 H2O -----------> 2 H2 + O2
water hydrogen oxygen
2 KClO3 -----------> 2 KCl + 3 O2
potassium chlorate potassium chloride oxygen
Substitution or Single Replacement Reactions A single free element replaces or is substituted for one of the elements in a compound. The free element is more reactive than the one its replaces.
Zn + 2 HCl ----------> H2 + ZnCl2
zinc hydrochloric acid hydrogen zinc chloride
Cu + 2 AgNO3 -----------> 2 Ag + Cu(NO3)2
copper silver nitrate silver copper (II) nitrate
H2 + 2 AgNO3 -----------> 2 Ag + 2 HNO3
hydrogen silver nitrate silver nitric acid
2 Na + 2 H2O -----------> 2 NaOH + H2
sodium water sodium hydroxide hydrogen
Metathesis or Double Displacement Reactions This reaction type can be viewed as an "exchange of partners." For ionic compounds, the positive ion in the first compound combines with the negative ion in the second compound, and the positive ion in the second compound combines with the negative ion in the first compound.
HCl + NaOH -----------> NaCl + HOH
hydrochloric sodium sodium water
acid hydroxide chloride
BaCl2 + 2 AgNO3 ----------> 2 AgCl + Ba(NO3)2
barium silver silver barium
chloride nitrate chloride nitrate
(precipitate)
CaCO3 + 2 HCl -----------> CaCl2 + H2CO3
calcium hydrochloric calcium carbonic
carbonate acid chloride acid
Explanation:
The vast number of chemical reactions can be classified in any number of ways. Under one scheme they can be categorized either as oxidation-reduction (electron transfer) reactions or non-oxidation-reduction reactions. Another completely different but common classification scheme recognizes
