What is the difference between acetic acid and acetic anhydride

Comparison of 1. basic information

1. molecular structure and composition

• Acetic Acid (Acetic Acid): The chemical formula is CHelevated COOH, and the molecular weight is 46.07g/mol. Acetic acid is a colorless liquid with an acidic odor. It is composed of carbon, hydrogen, and oxygen. The molecular structure contains a carboxylic acid group (-COOH) and a methyl group (-CH3).
• Acetic anhydride (Acetanilide) the chemical formula is CH �(NH) COOH and the molecular weight is 76.13g/mol. Acetic anhydride is a colorless crystal, commonly used in the preparation of acetic acid. It is composed of four elements: carbon, hydrogen, oxygen, and nitrogen. Its structure contains a benzene ring (C6H5) connected to a carboxamide group (-CO-NH2) and a carboxylic acid group (-COOH).

1. Physical Properties

• acetic acid is liquid at room temperature, with a density of about 1.05g/cm³ and a boiling point of 124.9°C.
• Acetic anhydride is a solid at room temperature, the color is colorless or yellowish crystals, the density is about 1.37g/cm³.

1. Chemical properties

• acetic acid is a dibasic weak acid that can neutralize with alkaline substances.
• Acetic anhydride is an anhydride formed by the reaction of acetic acid and ammonia (NH3) under heated conditions. It has similar acidity, but is less stable and easily decomposed.

comparison

1. differences in molecular structure and composition

• the molecular structure of acetic acid is relatively simple, containing only carboxylic acid groups, while the structure of acetic anhydride is complex, including benzene ring, carboxamide group and carboxylic acid group. Acetic anhydride can be regarded as a polycondensation product of acetic acid with aniline (aniline).

1. Use difference

• acetic acid mainly used in the preparation of vinegar, but also an important raw material in organic synthesis, such as the manufacture of esters, spices and so on. In addition, acetic acid is also widely used in medicine and food industry.
• acetic anhydride: Mainly used as an auxiliary agent for the production of acetic acid. In industrial production, acetic anhydride is reacted with ethanol under specific conditions to produce ethyl acetate, thereby producing acetic acid. In addition, acetic anhydride is also used in the synthesis of other organic compounds.

1. Reaction characteristics

• acetic acid is prone to esterification under acidic conditions and has neutralization characteristics under alkaline conditions.
• Acetic anhydride decomposes under acidic conditions and easily loses carboxylic acid groups. Therefore, it is necessary to control the reaction conditions in industrial applications to avoid the adverse effects of decomposition.

Comparison of 3. application areas

1. industrial Applications

• acetic acid in industrial production, acetic acid is widely used in the preparation of vinegar, ethanol, esters and other products. It is also used in the preparation of certain medicines and fragrances.
• acetic anhydride: Acetic anhydride is mainly used in the production of acetic acid, especially in the process of converting ethanol into acetic acid. In addition, acetic anhydride is also used in the synthesis of other chemicals, such as certain intermediates and polymer materials.

1. Environmental impact

• acetic acid may have a certain impact on the environment in industrial production, especially in water treatment and waste disposal.
• The stability of acetic anhydride is poor, but it usually exists in the form of auxiliary agents in industrial applications, and its impact on the environment is relatively small.

1. Storage and transportation

• acetic acid should be stored in a cool and dry place with good ventilation, away from direct sunlight and high temperature. The transport shall be in accordance with the relevant provisions for the packaging and storage of dangerous goods.
• Because of its crystalline granular form, acetic anhydride is usually packaged in granular form. Attention should be paid to moisture-proof and dust-proof during transportation to ensure that it will not be affected with moisture and deterioration during transportation.

The comparison

1. differences in molecular structure: the molecular structure of acetic acid is relatively simple, while the structure of acetic anhydride is more complex, including benzene ring and amide group.

2. Differences in chemical properties: acetic acid has strong acidity, and acetic anhydride as anhydride, its chemical properties are relatively stable, but it is easy to decompose under specific conditions.

3. Use difference: Acetic acid has a wide range of applications in industrial production, and acetic anhydride is mainly used as an auxiliary agent for the production of acetic acid, and its application range is relatively limited.

Acetic acid and acetic anhydride, although there are significant differences in molecular structure and use, but they play an important role in industrial production and chemical reactions. Understanding their differences and characteristics is of great significance for the rational use and selection of suitable chemicals.