How to distinguish between glyoxylic acid and formic acid

In the chemical industry, the differentiation of chemicals is a basic but important skill. Glyoxylic acid (Acid Acrin, chemical formula: C? H? O?) and formic acid (Formic Acid, chemical formula: HCOOH) are both acids, but they have significant differences in molecular structure, physical properties, chemical properties and application fields. This article will analyze in detail how to distinguish these two substances from multiple perspectives.

the structure and properties of

From the point of view of molecular structure, glyoxylic acid and formic acid have the molecular formula C₂ Helevated O₂ and HCOOH, respectively, and there is a significant difference in the number of carbon atoms. The molecular structure of glyoxylic acid is CH₂ = CHO₂, while the molecular structure of formic acid is HCOOH. Due to the different number of carbon atoms, there are significant differences in physical and chemical properties.

Glyoxylic acid is a colorless, odorless solid with a melting point of 5.5°C and a density of 1.49g/cm³. Formic acid is a colorless, pungent liquid with a melting point of 101.9°C and a density of 1.22g/cm³. It can be seen from the above properties that the appearance and touch of the two can be initially distinguished.

2. physical property differences

1. melting point and boiling point Glyoxylic acid has a low melting point (5.5°C) and is in a solid state at room temperature, while formic acid has a high melting point (101.9°C) and is in a liquid state at room temperature. This can be experimentally easily observation to determine the physical state of the two.

2. Density Glyoxylic acid has a density of 1.49g/cm³, while formic acid has a density of 1.22g/cm³. The difference in density can help quickly determine the type of substance.

3. Smell and taste Glyoxylic acid has a faint pungent odor, while formic acid has a strong rotten odor. This can be distinguished by smell or taste.

4. Solubility Glyoxylic acid is slightly soluble in water and readily soluble in ethanol. The solubility of formic acid in water and ethanol is higher, but the acidity of formic acid is stronger and the reaction activity is higher.

3. chemical differences

1. Acid strength Formic acid is more acidic than glyoxylic acid, and its pKa value is about 3.75, while the pKa value of glyoxylic acid is about 4.26. The strength of acidity directly affects their chemical reaction characteristics.

2. reactivity Formic acid shows stronger activity in chemical reactions, especially in redox reactions. Glyoxylic acid is relatively stable, low reactivity.

3. Preparation method Formic acid can be obtained by oxidation of ethanol, while glyoxylic acid can be obtained by oxidation of acetaldehyde. The preparation methods of the two methods are different, and the preparation difficulty is also different.

4. Practical Application Differences

1. Industrial Applications Formic acid is mainly used in the preparation of acetic acid, glyoxylic acid and other derivatives. In the industrial application of glyoxylic acid, it is mainly used for the synthesis of other organic compounds.

2. Drug Application Formic acid is often used for detoxification of drugs, while glyoxylic acid is mainly used as a preservative and food additive.

5. Summary and Precautions

From the above analysis, it can be seen that there are significant differences between glyoxylic acid and formic acid in many aspects. In practice, the two substances can be distinguished by observing the physical properties of the substance such as appearance, melting point, density, odor, etc., as well as the chemical properties such as acidity and reactivity. For professionals, mastering the difference between these two acids not only helps to improve the efficiency of experiments, but also makes more scientific decisions in practical work.

When distinguishing between glyoxylic acid and formic acid, special attention should be paid to the following points: one is to wear appropriate protective equipment during experimental operation, the other is to stay away from fire sources and strong oxidants, and the third is to operate in accordance with relevant safety regulations. With these precautions, the safety and efficacy of the experiment can be ensured.