Types of Chemical Reactions

Q. Explain types of Chemical Reactions with example:-

There are six general types of chemical reactions:

1. Combustion Reaction:

A Combustion reaction occurs when Oxygen reacts with any other compound to form Carbon Dioxide and water. It is a exothermic reaction which means heat energy is produced during this reaction.

Example: When methane gas (CH₄) reacts with oxygen (O₂) to produce one mole of water (H₂O) and one mole of carbon dioxide (CO₂)

CH₄ + O₂ =====> H₂O + CO₂

2. Addition or Combination or Synthesis Reaction:

A type of chemical reaction in which two or more compounds react with each other and form a single compound. In this reaction energy is released in form of heat and light.

Example: When one mole of carbon (C) reacts with one mole of oxygen (O₂) to form one mole of Carbon dioxide (CO₂)

C + O₂ =====> CO₂

3. Decomposition Reaction:

A decomposition reaction is the opposite of combination reaction. In this type of chemical reaction a single compound breaks down to form two or more compounds.

Example: When Hydrogen Peroxide (H₂O₂) is heated it decomposes into one mole of water (H₂O) and one mole of oxygen (O₂)

H₂O₂ =====> H₂O + O₂

4. Substitution or Single Displacement Reaction:

A reaction is called Single displacement or substitution reaction if one element in a compound changes its place with another element in a compound.

Example: When zinc (Zn) reacts with copper chloride (CuCl₂) as a result zinc changes its place and replaces copper from copper chloride to form zinc chloride (ZnCl₂) and copper is left alone.

Zn + CuCl₂ =====> ZnCl₂ + Cu

5. Double Displacement Reaction:

A reaction is called Double displacement reaction if two elements in their respective compounds change their partners to form new compounds. In a double displacement reaction usually anions and cations of two different compounds change their places.

Example: A reaction in which Potassium Iodine (KI) reacts with Lead Nitrate (Pb(NO₃)₂) and as a result potassium from the compound of potassium iodine changes its partner with lead in the compound of lead nitrate to form Lead Iodine (PbI) and  Potassium Nitrate (KNO₃)

KI + Pb(NO₃)₂ =====> PbI₂ + KNO₃

6.Neutralization or Acid-Base Reaction:

It is a special type of Double Displacement reaction in which an Acid reacts with a Base. The H⁺ of an acid react with OH^- of a base which causes the formation of an ionic Salt and Water.

Example: When Hydrochloric Acid (HCl) reacts with Sodium Hydroxide (NaOH) and form Sodium chloride salt (NaCl) and water (H₂O)

HCl + NaOH =====> NaCl + H₂O