True or false: (a) If a substance is oxidized, there must be more oxygen in the substance.

Verified step by step guidance

1. Understand the concept of oxidation: Oxidation is a chemical process where a substance loses electrons. It does not necessarily involve the addition of oxygen.
2. Consider the historical context: Historically, oxidation was associated with the addition of oxygen, but in modern chemistry, it is defined by the loss of electrons.
3. Evaluate the statement: The statement suggests that oxidation always involves more oxygen in the substance, which is not true in the context of electron transfer.
4. Provide an example: For instance, when iron rusts, it combines with oxygen, but in other oxidation reactions, such as the oxidation of hydrogen to form protons, no oxygen is involved.
5. Conclude the analysis: Therefore, the statement is false because oxidation is defined by electron loss, not necessarily by the presence of oxygen.

Key Concepts

Oxidation and Reduction

Oxidation refers to the loss of electrons by a substance, while reduction is the gain of electrons. These processes are part of redox reactions, where one species is oxidized and another is reduced. Importantly, oxidation does not necessarily involve the addition of oxygen; it can occur through the loss of hydrogen or electrons.

Oxygen's Role in Oxidation

While oxygen is commonly associated with oxidation, it is not a requirement for a substance to be oxidized. Oxidation can occur in reactions where oxygen is absent, such as in the case of metals reacting with halogens. Therefore, the presence of more oxygen does not define whether a substance is oxidized.

Stoichiometry in Chemical Reactions

Stoichiometry involves the calculation of reactants and products in chemical reactions based on the conservation of mass. Understanding stoichiometry helps clarify how changes in the composition of substances occur during oxidation and reduction, emphasizing that the amount of oxygen does not dictate the oxidation state of a substance.