Define different types of chemical reaction …

Chemical reactions can be classified in following types:

• Combination Reaction

  Example: When magnesium is burnt in air (oxygen), magnesium oxide is formed. In this reaction, magnesium is combined with oxygen.

  <i>Mg + O₂ </i> →<i>2MgO</i>

  <i>Magnesium + Oxygen ⇨ Magnesium oxide</i>

• Decomposition Reaction

  Example: When calcium carbonate is heated, it decomposes into calcium oxide and carbon dioxide

  <i>CaCO₃ </i> →<i> CaO + CO₂</i>

• Displacement Reaction

  Example: When zinc reacts with hydrochloric acid, it gives hydrogen gas and zinc chloride.

  <i>Zn + 2HCl </i> →<i>ZnCl₂ + H₂</i>

• Double Displacement Reaction

  Example: When solution of barium chloride reacts with the solution of sodium sulphate, white precipitate of barium sulphate is formed along with sodium chloride.

  <i>BaCl₂ + Na₂SO₄ </i> → <i>BaSO₄ + 2NaCl</i>

• Oxidation and Reduction Reaction

  Example: When iron reacts with air, it forms iron oxide (rust)

  <i>4Fe + 3O₂ </i> →<i> 2Fe₂O₃</i>