1) Combustion reaction: A combustion reaction is basically when oxygen combines with another compound to produce water and carbon dioxide. Combustion reactions are exothermic, which basically mean they produce heat. An example of this reaction is the burning of methane, which is shown by this equation CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (g).
2) Synthesis reaction: When two or more compounds combine to form a more complicated one, it is referred to as synthesis reaction. These are represented in the general form of:
A + B —> AB
One example of synthesis reaction is the combination of iron and sulfur to form iron (II) sulfide: 8Fe + S8 —>8FeS.
3) Decomposition reaction: Decomposition reaction is the opposite of a synthesis reaction- it occur when a complex molecule breaks down to make simpler ones. These reaction are represented by the general equation:
the electrolysis of water to make oxygen and hydrogen gas is one example of decomposition reaction: 2H2O—>2H2+O2
4) Single displacement reaction: This reaction is basically when one element trade place with another element in a compound. Single displacement can be represented using the general equation of:
Magnesium replacing hydrogen in water to make magnesium hydroxide and hydrogen gas is one example of single displacement reaction: Mg+2H2O —> Mg(OH)2+H2
5) Double displacement reaction: This reaction occurs when the anions and cations of two different molecules switch places, as a result forming two entirely different compounds. Theses reaction are represented in the general form of: AB+CD —>AD+CB
The reaction of lead(II) nitrate with potassium iodide to form lead (II) iodide and potassium nitrate is one such example of on double displacement reaction: Pb(NO3)2 + 2 KI —> PbI2 + 2 KNO3
6) Acid-base reaction: Acid-base reaction is a special kind of double displacement reaction that occurs when an acid and base react with each other. What happen is that the H+ ion in the acid reacts with the OH– ion in the base, causing the formation of water. Usually the product of this kind of reaction is some ionic salt and water:
HA + BOH —> H2O + BA
The reaction of hydrobromic acid (HBr) with sodium hydroxide is one example of acid-base reaction. The equation for this reaction is: HBr + NaOH —> NaBr + H2O