The correct option is **C. Oxidation involves the loss of electrons, while reduction involves the gain of electrons.** ### Detailed Explanation: 1. **Understanding Oxidation and Reduction:** - **Oxidation** is defined as the process where a substance loses electrons. When a substance loses electrons, its oxidation state increases. This can also be associated with the loss of hydrogen or the gain of oxygen. - **Reduction**, on the other hand, is the process where a substance gains electrons. When a substance gains electrons, its oxidation state decreases. This can also be associated with the gain of hydrogen or the loss of oxygen. 2. **Why Option C is Correct:** - Option C accurately describes the fundamental definitions of oxidation and reduction in terms of electron transfer. In a redox (reduction-oxidation) reaction, one species is oxidized (loses electrons) while another is reduced (gains electrons). This electron transfer is the hallmark of redox reactions. - For example, in the reaction between zinc and copper sulfate: \[ \text{Zn (s)} + \text{CuSO}_4 (aq) \rightarrow \text{ZnSO}_4 (aq) + \text{Cu (s)} \] - Zinc (Zn) loses two electrons to become Zn²⁺, thus it is oxidized. - Copper (Cu²⁺) gains those two electrons to become Cu, thus it is reduced. 3. **Why the Other Options are Incorrect:** - **Option A: Oxidation involves the gain of electrons, while reduction involves the loss of electrons.** - This statement is incorrect because it reverses the definitions of oxidation and reduction. Oxidation is characterized by the loss of electrons, not the gain. - **Option B: Oxidation is the process of losing hydrogen, while reduction is the process of gaining hydrogen.** - While it is true that oxidation can involve the loss of hydrogen and reduction can involve the gain of hydrogen, this definition is too narrow. Oxidation and reduction are more broadly defined by electron transfer, making this option misleading. - **Option D: Oxidation and reduction both involve the transfer of electrons to the same species.** - This statement is incorrect because oxidation and reduction involve the transfer of electrons between different species. One species is oxidized (loses electrons) and another is reduced (gains those electrons). They cannot occur in the same species simultaneously. ### Common Pitfalls: - Students often confuse oxidation with the loss of hydrogen and reduction with the gain of hydrogen, which can lead to misunderstanding. It is crucial to remember that the core concept revolves around electron transfer. - Another common mistake is to mix up the definitions of oxidation and reduction, especially in complex reactions where multiple species are involved. ### Revision Summary: - **Oxidation**: Loss of electrons (increase in oxidation state). - **Reduction**: Gain of electrons (decrease in oxidation state). - In redox reactions, one species is oxidized while another is reduced. - Remember the mnemonic: "OIL RIG" (Oxidation Is Loss, Reduction Is Gain) to help recall the definitions.