3. Ca(OH)₂ + H₂SO₄ → CaSO₄ + 2 H₂O represents a neutralization reaction.
Step-by-step explanation:
Neutralization reaction is a reaction in which an acid reacts with a base to form a slat and water.
First reaction is the decomposition reaction in which the reactant is decomposed to form 2 or more products.
Second one is the combustion reaction in which methane is burnt in presence of oxygen.
Third one is the Neutralization reaction, in which calcium hydroxide (base) reacts with sulfuric acid (acid) to form a (salt) calcium sulfate and water.
Fourth reaction is nothing but the double displacement reaction in which the ions exchanged their positions there by forming two new products.