Understanding Neutralisation Reactions

A neutralisation reaction is a specific type of chemical reaction where an acid and a base react quantitatively with each other. In a reaction in water, this happens when the H⁺ (acid) and OH^- (base) ions react to form water (H₂O).

Neutralisation reactions typically result in the formation of a salt and water.

Analysing Reaction Types

Let's examine the given options to see which fits the definition of neutralisation:

• Single displacement: One element replaces a similar element in a compound (e.g., Zn + CuSO₄ → ZnSO₄ + Cu). This is not neutralisation.
• Double displacement: Ions from two compounds switch places to form two new compounds (e.g., AB + CD → AD + CB). Neutralisation reactions, like acid-base reactions (e.g., HCl + NaOH → NaCl + H₂O), fit this category where the cation of one reactant combines with the anion of the other, and vice versa.
• Decomposition: A single compound breaks down into two or more simpler substances (e.g., 2H₂O₂ → 2H₂O + O₂). This is not neutralisation.
• Combustion: A substance reacts rapidly with an oxidant, usually oxygen, to produce heat and light (e.g., CH₄ + 2O₂ → CO₂ + 2H₂O). This is not neutralisation.

Identifying the Correct Reaction Type

Since neutralisation involves the exchange of ions between reacting acid and base to form salt and water, it fundamentally follows the pattern of a double displacement reaction.

Therefore, a neutralisation reaction is a type of double displacement reaction.