Question

A species whose oxidation number increases in a reaction is

Answer 1

A species whose oxidation number increases in a chemical reaction is being oxidized. This is observed in redox reactions, where the oxidation number signifies the loss of electrons for that element.

Step-by-step explanation:

A species whose oxidation number increases in a reaction is said to be oxidized. This is a central concept in redox reactions, where there is always a simultaneous change in the oxidation numbers of atoms. During these reactions, if the oxidation number of an element increases, it means that the element has lost electrons and has undergone oxidation.

For example, in the reaction C (s) + O2 (g) → CO2 (g), the oxidation number of carbon increases from 0 in the elemental state to +4 in carbon dioxide. This indicates that carbon has been oxidized. Conversely, the oxidation number of oxygen decreases from 0 to -2, meaning that oxygen has been reduced.

Thus, a complete redox reaction includes both oxidation and reduction processes. Species in high oxidation states usually act as oxidants, while those in low oxidation states act as reductants.

Answer 2

A species whose oxidation number increases in a reaction is oxidized (reducing reagents or reactant).
For example, balanced chemical reaction: 2KClO₃ → 2KCl + 3O₂.
Oxygen in the reactant state has oxidation number -2 (+1 + 5 + 3 · x = 0) and it is oxidized to 0 (in molecule of oxygen) in the product state.