Types of Chemical Reactions with Examples

Types of Chemical Reactions with Examples

1) Combustion/Burning Reactions:

Reaction of some combustible matters with oxidizing elements like oxygen is called combustion reactions.After these reactions oxidized products are produced. In general, these reactions are exothermic.To have combustion reaction we must have; combustible matters, oxidizing element and necessary temperature.Examine following combustion reaction samples;

Ca(s) + 1/2O2(g) → CaO(s) + Heat

2Fe(s) + 3/2O2(g) → Fe2O3(s) + Heat

  • If compounds including C and H elements  burn with necessary O2, products are H2O and CO2.


CH4(g) + 2O2(g) → CO2(g) + 2H2O(g) +Heat

C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(g) + Heat

2) Combination/Synthesis Reactions:

More than one matters combine and form new matter is called combination or synthesis reactions.

X + Y → XY

2H2(g) + O2 → 2H2O(l)

N2(g) + 3H2(g) → 2NH3(g)

3) Decompositions/Analysis Reactions:

These reactions are opposite of combination reactions. One compound breaks down to other compounds or elements in decomposition reactions. For example;

XY → X + Y

2H2O(l) → 2H2(g) + O2(g)

CaCO3(s) → CaO(s) + CO2(g)

4. Displacement/Replacement Reactions:

An element reacts with compound and replace with an element of that compound. For example;


Mg(s) + Cu(NO3)2(aq) → Mg(NO3)2(aq) + Cu(s)

Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)

If two elements or compounds replace, we call them double displacement reactions. For instance;

AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq)

Ag replace with Na and NO3 replace with Cl.

5. Acid and Base Reactions (Neutralization Reactions):

Acidic and basic matters react with and we call these reactions neutralization reactions .

Acid + Base → Salt +Water


Acid + Base → Salt


HCl + NaOH → NaCl + H2O

3H2SO4 + 2Al(OH)3 → Al2(SO4)3 + 6H2O

SO3 + Na2O → Na2SO4

6. Metal + Acid Reactions:

When metals react with acids, salt and hydrogen are produced.

Metal + Acid → Salt + H2(g)

Mg + 2HCl → MgCl2 + H2(g)

Some of the metals like, Pt, Au, Hg, Cu and Ag react with acids but H2 gas is not produced instead H2O is produced.

Ag + 2HNO3 → AgNO3 + NO2(g) +H2O

7. Metal + Base Reactions:

Since metals have base property, they do not react with bases. However, there are some exceptions like Zn and Al.


Al + 3KOH → K3AlO3 + 3/2H2(g)

Zn + 2NaOH → Na2ZnO2 + H2(g)

8. Exothermic and Endothermic Reactions:

Reactions releasing heat are called exothermic reactions and reactions absorbing heat are called endothermic reactions.


2H2(g) + O2(g) → 2H2O + 68 kcal Exothermic Reaction

C(s) + 1/2O2(g) → CO2(g) + 94 kcal Exothermic Reaction

2NH3(g) + 22kcal → N2(g) + 3H2(g) Endothermic Reaction

Chemical Reactions Exams and Problem Solutions