What type of reaction is characterized by the transfer of electrons between species?

• A. Decomposition reaction
• B. Synthesis reaction
• C. Redox reaction
• D. Combustion reaction

Answer: (C)

The correct answer is characterized by the transfer of electrons between species, which defines a redox reaction. In redox reactions, there are two key processes: oxidation, which involves the loss of electrons, and reduction, which involves the gain of electrons. This transfer of electrons is fundamental to the reaction, influencing the oxidation states of the reactants involved.

Redox reactions are pivotal in many biological and chemical processes, from cellular respiration to combustion. For instance, when organic molecules are oxidized, they lose electrons, while another species, typically a molecular oxygen or a metal ion, gains those electrons, effectively reducing itself.

In contrast, other types of reactions such as decomposition and synthesis do not primarily focus on the transfer of electrons between species. Decomposition reactions involve the breaking down of a compound into simpler substances, while synthesis reactions involve the combination of two or more reactants to form a more complex product. Combustion reactions are a specific type of redox reaction that involves the reaction of a substance with oxygen, producing heat and light, but they are not solely defined by the electron transfer aspect alone.

Hence, redox reactions uniquely illustrate the principle of electron transfer, highlighting their importance in both chemistry and biological systems.