Which type of chemical reaction is exemplified by the following equation? 2HCl (aq) + Mg(OH)₂ (s) → 2H₂O (l) + MgCl₂ (aq)

Decomposition reactions involve a single compound breaking down into two or more simpler substances. The provided equation showcases the combination of two reactants rather than a single substance breaking apart. Therefore, it does not fit the criteria for a decomposition reaction.

Combustion reactions typically involve a substance reacting with oxygen, producing heat and light, often resulting in carbon dioxide and water as products. The reaction in question does not involve oxygen or produce energy in the form of heat and light, thus it does not represent a combustion reaction.

Synthesis reactions occur when two or more reactants combine to form a single product. Although the products of the given equation include two products (water and magnesium chloride), it starts with two reactants and does not yield a single, more complex product. Thus, it does not qualify as a synthesis reaction.