A few reactions are listed below:
I. Hydrogen + Oxygen `to` Water II. Calcium oxide + Carbon dioxide `to` Calcium carbonate III. Silver nitrate + Copper `to` Copper nitrate + Silver IV. Sodium hydroxide + Hydrochloric acid `to` Sodium chloride + Water V. Sodium nitrate `to` Sodium nitrite + Oxygen
Now, read the given passage and fill in the blanks by selecting an appropriate option. Reaction(s) ___(i) is/are combination reaction(s), reaction(s) ____(ii) is/are single displacement reaction(s), while reaction____(iii) is a decomposition reaction. Reaction(s)____ (iv) is/are neutralisation reaction(s) and heat energy is ____(v) in this/these reaction(s).

Answer

B

Explanation

Hydrogen + Oxygen `to` Water
Calcium oxide + Carbon dioxide `to` Calcium carbonate Both the reactions are combination reactions as two substances are combining to form a new substance.
Silver nitrate + Copper `to` Copper nitrate + Silver
Copper is displacing silver from its salt solution, hence it is al single displacement reaction.
Sodium nitrate `to` Sodium nitrite + Oxygen
Sodium nitrate is decomposing into sodium nitrite and oxygen hence, it is a decomposition reaction.

Acid and base combine to form salt and water hence, it is a neutralisation reaction which is exothermic in nature.