Are the substances shown in italics undergoing oxidation or reduction?
(c) Wine (containing ethanol, CH₃CH₂OH) sours to vinegar (CH₃COOH).

Verified step by step guidance

1. Identify the initial and final substances in the reaction: Ethanol (CH₃CH₂OH) is converted to acetic acid (CH₃COOH).
2. Determine the oxidation states of carbon in both ethanol and acetic acid. In ethanol, the carbon bonded to the hydroxyl group (CH₃CH₂OH) is typically in a lower oxidation state compared to the carbon in the carboxyl group (CH₃COOH) of acetic acid.
3. Recognize that oxidation involves an increase in oxidation state, while reduction involves a decrease in oxidation state.
4. Compare the oxidation states: If the carbon in ethanol has increased its oxidation state in acetic acid, then ethanol is undergoing oxidation.
5. Conclude that since the carbon in ethanol is oxidized to form acetic acid, the process of wine souring to vinegar involves the oxidation of ethanol.

Key Concepts

Oxidation and Reduction

Oxidation and reduction are chemical processes that involve the transfer of electrons between substances. Oxidation refers to the loss of electrons, while reduction involves the gain of electrons. These processes are often coupled, meaning that when one substance is oxidized, another is reduced. Understanding these concepts is crucial for analyzing chemical reactions, such as the conversion of ethanol to acetic acid.

Ethanol to Acetic Acid Conversion

The conversion of ethanol (CH₃CH₂OH) to acetic acid (CH₃COOH) is a classic example of an oxidation reaction. In this process, ethanol is oxidized, losing electrons and forming acetic acid. This transformation is commonly observed in the fermentation process, where ethanol is produced and subsequently oxidized to vinegar. Recognizing this reaction helps in identifying the roles of the substances involved.

Redox Reactions

Redox reactions, short for reduction-oxidation reactions, are fundamental chemical reactions that involve the transfer of electrons. In the context of the question, the souring of wine to vinegar exemplifies a redox reaction where ethanol is oxidized to acetic acid. Understanding redox reactions is essential for predicting the behavior of substances in chemical processes and for grasping the underlying principles of many biological and industrial reactions.