How to distinguish between formic acid acetic acid methyl acetate

Formic acid, acetic acid and ethyl acetate are three common organic compounds in the chemical industry. They have some similarities in chemical and physical properties, but they also have significant differences. Distinguishing these three substances is very important for experimental operation, production management and quality control. The following is a detailed analysis of how to distinguish between formic acid, acetic acid and ethyl acetate from multiple perspectives.

1. Appearance and smell

This is the most intuitive way to distinguish these three substances.

• Formic acid: Colorless liquid, has a strong sour taste, the smell is similar to vinegar.
• Acetic: Colorless liquid, slightly acidic in smell, similar to concentrated vinegar.
• Ethyl: Colorless liquid, smell similar to apple, not sour.

These three substances can be distinguished directly by observing the color and smell of the liquid. The odors of formic acid and acetic acid are very similar, but the odor of ethyl acetate is completely different.

Question field: How to distinguish between formic acid and acetic acid?

2. Density and boiling point

Density and boiling point are the important basis for distinguishing these three substances.

• Formic acid: density is 1.73g/cm³, boiling point is 70 ℃.
• Acetic: density 1 and 1.049g/cm³, boiling point 77.4 ℃.
• Ethyl: density 0.902g/cm³, boiling point 77 ℃.

These three substances can be distinguished by measuring the density and boiling point of the liquid. It should be noted that the boiling points of acetic acid and ethyl acetate are very close (both 77°C), so they can be further distinguished by heating and concentration.

Question Field: How to distinguish between acetic acid and ethyl acetate?

3. Acid strength

The strength of acidity is the key to distinguish between formic acid and acetic acid.

• Formic acid: is a strong acid, with strong corrosive.
• Acetic: is a strong acid, acid is weaker than formic acid, but still has a certain acidity.

The strength of the acidity can be verified by chemical reaction. For example, sodium carbonate was added to the two substances and the amount of gas generated was observed. The formic acid reaction produces more gas because it is more acidic.

Question field: How to distinguish between formic acid and acetic acid? It can be distinguished by the strength of acidity.

4. Solubility and storage methods

Formic acid, acetic acid and ethyl acetate have different solubilities, which can also be used to distinguish them.

• Formic: Soluble in water and organic solvents.
• Acetic: soluble in water and organic solvents, but acidic than formic acid.
• Ethyl: slightly soluble in water, soluble in organic solvents.

Because ethyl acetate is slightly soluble in water, it can be separated from water by liquid separation, while formic acid and acetic acid are not easy to separate.

Question field: How do you distinguish ethyl acetate from the other two substances? You can observe its solubility or use a liquid separation method.

5. Application field

Understanding the application areas of these three substances can also help distinguish them.

• Formic acid: mainly used in the manufacture of vinegar, urea and other products, but also used in some chemical synthesis.
• Acetic: widely used in vinegar production, spice manufacturing and pharmaceutical fields.
• Ethyl: Mainly used in the production of ester compounds, such as synthetic herbicides and edible oils.

Identifying substances can also be helped by understanding their field of application.

Summary

Formic acid, acetic acid and ethyl acetate can be clearly separated from each other by appearance and smell, density and boiling point, acidity, solubility and application field. In practice, accurate discrimination can be achieved by combining physical property tests (such as density measurement, odor and smell) and chemical reactions (such as acidity test). Mastering these methods can greatly improve the efficiency of experiments and production, and ensure product quality and operational safety.