A Level Chemistry OCR Practice Exam

The type of reaction that involves the loss of electrons is oxidation. In the context of redox (reduction-oxidation) reactions, oxidation is defined as the process where an atom, ion, or molecule loses electrons. This loss leads to an increase in the oxidation state.

When a substance undergoes oxidation, it may combine with oxygen or it may lose hydrogen, among other reactions. This is fundamental in various chemical processes, such as combustion, respiration, and photosynthesis, where substances like glucose or hydrocarbons are oxidized to release energy.

In contrast, reduction is characterized by the gain of electrons, leading to a decrease in oxidation state. Hydrolysis and neutralization are not primarily associated with electron transfer; hydrolysis involves the reaction of a substance with water, while neutralization involves the reaction between an acid and a base to produce salt and water. Understanding the distinction between oxidation and reduction is crucial for mastering redox chemistry, as they always occur simultaneously in a coupled reaction.