Chemical Reactions

Formation of a Molecular Compound in a double-displacement reaction
Another kind of double-replacement reaction is one that produces a molecular compound as one of its products. Many reactions can be given as examples in this category which produce water.

For example,when aqueous hydrochloric acid is reacted with aqueous sodium hydroxide, the products are aqueous sodium chloride and water:
The equation can be written as follows

            HCl(aq)+NaOH(aq)   \( \to \) NaCl(aq)+H₂O(l)

Formation of a Molecular Compound in a double-displacement reaction
One typical example of double displacement reaction is neutralization reactions. Hydrogen ion (H⁺) from acid and hydroxyl ions (OH^-) from base combine to form salt and water

For example, When sodium hydroxide reacts with hydrochloric acid, H⁺ ion of hydrochloric acid gets displaced by Na⁺ ion to form a salt, NaCl and OH^- ion in sodium hydroxide combines with H⁺ ion to form water, H₂O. Thus, the neutralization reaction is an example of double displacement reaction.
The equation can be written as follows:

HCl(aq)+NaOH(aq)  \( \to \)   NaCl(aq)+H₂O(l)