Question 7 - MCQs from NCERT Exemplar - Chapter 1 Class 10 - Chemical Reactions and Equations

Which among the following is(are) double displacement reaction(s)?

(i) Pb + CuCl ₂ → PbCl ₂ + Cu

(ii) Na ₂ SO ₄ + BaCl ₂ → BaSO ₄ + 2NaCl

(iii) C + O ₂ → CO ₂

(iv) CH ₄ + 2O ₂ → CO ₂ + 2H ₂ O

(A) (i) and (iv) 

(B) (ii) only

(C) (i) and (ii) 

(D) (iii) and (iv)

Answer

A double displacement reaction is the one in which the two reacting species exchange their ions . 

Let’s look at all the options

1. (i) is an example of a single displacement reaction as only one ion is being exchanged.
2. (ii) is an example of a double displacement reaction because both of the reacting compounds are exchanging ions.
3. (iii) is an example of combination reaction because two substances are combining to form a single product.
4. (iv) is a redox reaction where CH ₄ is getting oxidized and O ₂ is getting reduced.

So, the correct answer is (b) (ii) only