Question 18 - MCQs from NCERT Exemplar - Chapter 1 Class 10 - Chemical Reactions and Equations

Which of the following are combination reactions?

(A) (i) and (iii) 

(B) (iii) and (iv)

(C) (ii) and (iv) 

(D) (ii) and (iii)

Answer

When two or more substances react to form a single product , it is known as a combination reaction.

Here,

• The first reaction (i) is an example of decomposition reaction because KClO ₃ is decomposing to form KCl and O ₂
• In the second (ii) and and third (iii) reaction, two reactants are combining to form a single product, so, these are combination reactions .
• The fourth reaction (iv) is a displacement reaction because Zn is displacing Fe from its salt solution.

So, the correct option is (d) - (ii) and (iii)