Chemistry Regents Practice Test 2025 – Complete Prep Resource

A decomposition reaction is characterized by the process of breaking down a single compound into two or more simpler products. In this type of reaction, a compound undergoes a transformation that results in the separation of its constituent elements or simpler compounds. For example, when water (H2O) is decomposed by electrolysis, it breaks down into hydrogen gas (H2) and oxygen gas (O2).

This reaction type is significant in various chemical processes and industrial applications, as it allows for the analysis and utilization of the individual components of a compound. Understanding decomposition reactions is crucial for recognizing how complex substances can be transformed into simpler substances under specific conditions, further illustrating the principles of chemical change and conservation of mass.

In contrast, synthesis reactions involve the combination of two or more substances to form a new, more complex compound. Single displacement reactions entail the replacement of one element in a compound with another element, while double displacement reactions involve the exchange of ions between two compounds. Each of these other reaction types serves different purposes in chemistry but does not involve the breakdown into simpler products as decomposition does.