Final answer:
In an oxidation-reduction reaction, oxidation is the loss of electrons (indicated by an increase in oxidation number), while reduction is the gain of electrons (indicated by a decrease in oxidation number). The identification of oxidation and reduction is done by examining electron transfer, specifically through changes in the oxidation numbers of the elements involved.
Step-by-step explanation:
To analyze the components of an oxidation-reduction reaction, we look for a change in oxidation numbers of the reactants. To identify oxidation, which is the loss of electrons, we find the element whose oxidation number increases. Conversely, reduction is the gain of electrons, indicated by a decrease in oxidation number. To demonstrate this in a reaction, we would list the oxidation numbers and observe the changes.
For example, if we considered the reaction of iron (II) oxide with carbon monoxide, we would assign oxidation numbers and observe that the iron is reduced (its oxidation state decreases) and carbon is oxidized (its oxidation state increases).
Which specific test can help us identify where the oxidation or reduction occurred within a reaction? It is c) By examining electron transfer. Neither a color change, a temperature change, nor a pressure change can directly demonstrate the transfer of electrons.