10 Examples of Combination Reaction Class 10

In this post, we will discuss about examples of combination reactions related to class 10 science.

What is combination reaction?

When two or more reactants react to form one single new substance(product), the reaction is known as combination reaction.

Combination reactions are also known as addition reactions.

In a combination reaction, new bonds are formed.

We can represent a combination reaction in a simple way

A+ B  → AB

Examples of Combination Reactions

   1.When nitrogen reacts with hydrogen

   2.When magnesium reacts with oxygen

   3.When coal is burnt

   4.When quick lime is added to water

   5.When calcium oxide reacts with carbon dioxide

   6. When nitrogen reacts with oxygen

   7.When hydrogen reacts with chlorine

   8.When sodium reacts with oxygen

   9.When ammonia reacts with hydrochloric acid

  10. When sodium reacts with chlorine

 

   1.Ammonia is produced when nitrogen reacts with hydrogen

   N₂ + 3H₂  → 2NH₃

 So, in this reaction nitrogen and hydrogen are two reactants

   2.When magnesium wire is burnt, it reacts with oxygen to form white powder of magnesium oxide.

   2Mg + O₂ → 2MgO

   3. Coal is allotrope of carbon. When coal is brunt, it produces carbon dioxide and heat

   C+ O₂ →CO₂

   4. Slaked lime is produced when calcium oxide (quick lime) is added to water, an exothermic reaction occurs.

 CaO + H₂O → Ca(OH)₂

   5.Calcium carbonate is produced when calcium oxide reacts with carbon dioxide.

 CaO + CO₂ → CaCO₃

   6.Nitrogen oxide is formed when nitrogen reacts with oxygen.

   

    N₂+ O₂ →2NO

    7.Hydrogen reacts with chlorine to form hydrochloric acid.

    H₂ + Cl₂ →2HCl

   8. Sodium oxide is formed when sodium reacts with oxygen

   4Na + O₂→ 2Na₂O

    9.Ammonium chloride is formed when ammonia reacts with hydrochloric acid.

    NH₃ + HCl → NH₄Cl

   10.   Sodium chloride is formed when sodium reacts with chlorine.

   2Na  + Cl₂ →2NaCl

   These are the examples of combination reaction.

    Multiple choice question

    1. What is another name of combination reaction?

   a. Substitution reaction

   b.Addition reaction

   c. Decomposition reaction

   d.Displacement reaction

Correct answer –(b)- Addition reaction

2.Which equation represents the combination reaction?

a. AB →A + B

b.A+ B →AB

c. A+ B →C D

d.AB + C →CB +A

Correct answer –(b) A+ B →AB

3.What is the formula of white powder formed when magnesium reacts with oxygen?

    a. MgO

   b.`Mg_2O`

   c. ``MgO_2`

   d.None of these

Correct answer –(a)MgO

4.Which gas is produced when coal is burnt?

a.   `CO2`

b.CO

c. `CH_4`

d.`H_2`

Correct answer –(a) `CO_2`

5.What is the correct chemical equation when sodium reacts with oxygen?

a. `2Na + O_2 →2NaO_2`

b.`4Na + O_2 →2Na2O`

c. `2Na + O_2 →2NaO

d.`Na + O_2 →NaO_2`

Correct answer –(b)