How to distinguish between acetic acid and phenol

1. Physical properties of the difference

1.1 solubility

Acetic acid is slightly soluble in water, while its solubility in ethanol is higher, and even obvious stratification can be formed. In contrast, phenol is hardly soluble in water, but is well soluble in organic solvents such as benzene or chloroform. Therefore, the dissolution can be observed by adding water and organic solvent separately.

1.2 acid-base strength

Acetic acid is a strong acid with a low pH, while phenol is a weak acid with a high pH. The change in pH can be observed by using a glass rod to dip the liquid to be measured and a few drops on the glass sheet. Acetic acid turns the glass flake red, while phenol does not.

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Question: How can acetic acid and phenol be distinguished by their solubility?

Analysis: Acetic acid is slightly soluble in water, but highly soluble in organic solvents, while phenol is almost insoluble in water, but highly soluble in organic solvents. By adding water and organic solvent separately, the different solubilities of the two substances can be clearly seen.

2. Chemical reaction differences

2.1 metal reaction

When acetic acid encounters a metal such as zinc or iron, it will produce hydrogen and react, but it should be noted that acetic acid is highly acidic and the reaction may be violent. Phenol does not react with metals at room temperature, but may react weakly when encountering strong acids or strong oxidants.

2.2 neutralization reaction

Acetic acid is a strong acid that can react with basic substances such as sodium carbonate to produce carbon dioxide gas. As a weak acid, phenol will not react with alkaline substances, so different phenomena can be observed in neutralization experiments.

Question: How can acetic acid and phenol be distinguished by a metal reaction?

Analysis: Acetic acid will react with the metal when it meets the metal to produce hydrogen, while phenol will not react. Therefore, the two substances can be distinguished by adding a small amount of metal powder respectively and observing whether or not bubbles are generated.

3. Purpose and application of the difference

Acetic acid is mainly used in the manufacture of plastics, glass steel and other materials, while phenol is used in the manufacture of spices, drugs and so on. The application fields of these two substances are different and can be distinguished by their use.

4. Laboratory identification methods

4.1 water solubility identification method

The liquid to be tested was added to water and alcohol respectively, and the dissolution was observed. Acetic acid has a low solubility in water and a high solubility in alcohol, while the opposite is true for phenol.

4.2 pH paper test

Take a small amount of liquid to be tested, drop the indicator and observe the color change. Acetic acid turns the indicator red, while phenol does not.

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Question: How can acetic acid and phenol be distinguished by water solubility identification?

Analysis: Acetic acid is slightly soluble in water, but its solubility in alcohol is higher, while phenol is almost insoluble in water, but its solubility in alcohol is higher. By adding water and alcohol separately, the different solubility of these two substances can be clearly seen.

5. Practical application of the difference

Acetic acid and phenol are widely used in industrial production and daily life. Acetic acid is used to make materials such as plastics and glass steel, while phenol is used to make spices and medicines. Understanding the difference between these two substances can help us choose the right materials and reagents in practical work.

Conclusion

Acetic acid and phenol can be clearly distinguished through differences in physical properties, differences in chemical reactions, and differences in practical applications. The difference in physical properties is the most obvious, which can be distinguished by solubility, acid-base strength and so on. The difference in chemical reaction can be observed by metal reaction and neutralization reaction. Understanding the difference between these two substances is important for chemical experiments and industrial production.