Distinguishing Ethanol and Ethanoic Acid A Guide to Differentiation

how to differentiate between ethanol and ethanoic acid


Ethanol and ethanoic acid are two common compounds with distinct chemical properties and applications. Differentiating between these substances is crucial, as they serve various purposes in industries and everyday life. This article aims to provide a comprehensive understanding of how to differentiate between ethanol and ethanoic acid. By examining their chemical formulas, physical properties, chemical reactions, and common applications, readers will gain valuable insights into distinguishing these two compounds.

Chemical Formulas and Structures

The chemical formula for ethanol is C2H5OH, which represents a two-carbon chain (C2) with an attached hydroxyl group (-OH). In contrast, ethanoic acid is represented by the formula CH3COOH, indicating a single carbon chain (C) with a carboxyl group (-COOH) attached. The structural difference between the two compounds is significant, with ethanol possessing only one functional group (-OH), while ethanoic acid has both an -OH group and a carboxyl group (-COOH). This dissimilarity in functional groups affects their properties and reactivity.

Physical Properties

Ethanol is a clear, colorless liquid with a characteristic odor. It has a boiling point of 78.3°C and a density of approximately 0.79 g/cm³. Ethanoic acid, on the other hand, is a colorless liquid with a pungent odor reminiscent of vinegar. It boils at a higher temperature, around 118.1°C, and has a slightly higher density of approximately 1.05 g/cm³. These differences in boiling points and densities can be used as initial indicators to distinguish between the two substances. 

Chemical Reactions

A key aspect of differentiation lies in the chemical reactions exhibited by ethanol and ethanoic acid. One simple method is to perform a reaction with a carbonate or bicarbonate compound. Ethanoic acid reacts with carbonates or bicarbonates to produce carbon dioxide (CO2) gas, water (H2O), and a corresponding acetate salt. This effervescence and the formation of a salt can be observed visually. Ethanol, being a neutral compound, does not undergo this reaction. 

Another method to differentiate between the two is to use oxidation reactions. Ethanol can be oxidized to ethanoic acid using oxidizing agents such as potassium dichromate (K2Cr2O7) and acidified potassium permanganate (KMnO4). When ethanoic acid is subjected to oxidation, it does not undergo any significant change. This distinction can be confirmed by observing the color change in the oxidizing agent or conducting a redox titration.

Furthermore, the reactions with litmus paper or pH indicators can be employed. Ethanoic acid is an acid and turns blue litmus paper red. It also has a lower pH value, typically around 2.5. In contrast, ethanol is neutral and does not alter the color of litmus paper. It has a near-neutral pH value, typically around 7.

Applications and Uses

Ethanol finds extensive use as a solvent in industries, fuel additives, and alcoholic beverages. It is commonly used in the pharmaceutical and cosmetic sectors as well. Ethanoic acid, also known as acetic acid, is a primary component in vinegar and is widely used in the food industry for preservation, flavoring, and pickling. It also serves as an important chemical in the production of plastics, dyes, and solvents.

Frequently Asked Questions

How do you test to differentiate between ethanol and ethanoic acid?

Ethanoic acid and ethanol can be distinguished by litmus test as well as by sodium bicarbonate test.

Which of the following Cannot distinguish ethanol from ethanoic acid?

Option ( a) Na metal is the correct answer because other options ( b) ,( c) and ( d) are used to distinguish ethanol from ethanoic acid. Which of the following substances cannot be used to distinguish ethanol… Attention UPSC Students!


Differentiating between ethanol and ethanoic acid is essential due to their distinct properties and applications. By understanding their chemical formulas, physical properties, chemical reactions, and common uses, one can readily differentiate between these two compounds. Factors such as boiling point, density, reactions with carbonates, oxidation, litmus paper, and pH indicators provide valuable insights into their identification. As ethanol and ethanoic acid play diverse roles in various industries and everyday life, the ability to differentiate between them is crucial for accurate application and safety considerations.

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