Difference between acetic anhydride and acetic acid

In the field of chemical engineering, acetic anhydride and acetic acid are two closely related but distinct concepts, and there are significant differences in chemical structure, physical properties, and uses. In order to help professionals better understand and apply these two concepts, this article will analyze the difference between acetic anhydride and acetic acid in detail from multiple angles.

Comparison of 1. Basic Chemical Knowledge

1. chemical formula and structure The chemical formula of acetic anhydride is C? H? O?, which is composed of three elements: carbon, hydrogen and oxygen. It is a kind of oxygen acid, molecular structure with two hydroxyl groups and a carboxyl group, with strong oxidation. The chemical formula of acetic acid is CH3COOH, the structure contains an acetic acid group, the molecular weight is small, with weak acidity.

2. Preparation method Acetic anhydride is usually obtained by oxidation of ethanol in the presence of a catalyst, and the process is complex and requires conditions such as high temperature and high pressure. Acetic acid can be generated by the reaction of ethanol and copper oxide or acetaldehyde and water vapor under the action of a catalyst, and the process is relatively simple.

Comparison of physical and chemical properties of 2.

1. Physical Properties Acetic anhydride has a high melting point and boiling point, density, high viscosity, melting point of 143.5 ℃, boiling point of up to 215 ℃. Acetic acid has a lower melting point of 83.8°C, a boiling point of 118°C, a smaller density, and a moderate viscosity.

2. Chemical properties Acetic anhydride is easy to decompose under acidic conditions, while acetic acid has strong stability and is not easy to decompose. The molecular structure of acetic anhydride is easily oxidized, and vinegar, acid stability is better.

Differences in 3. application areas

1. Different uses Acetic anhydride is mainly used in the production of ethyl acetate, which is an important intermediate and has a wide range of uses in petrochemical industry. Acetic acid is widely used in medicine, food, industry and other fields, is an important chemical raw material.

2. chemical reaction characteristics Acetic anhydride is easy to decompose at high temperature, while acetic acid has strong stability and is not easy to decompose. This difference needs to be used in actual production to avoid runaway reactions.

4. environmental protection and safety considerations

1. Security Features Acetic anhydride may produce hazardous gases during storage and use, and operators need to wear protective equipment. Acetic acid is relatively safe and produces less harmful gases during operation.

2. Environmental impact The production of acetic anhydride may cause greater pollution to the environment, while the production of acetic acid is relatively mild and has less impact on the environment.

5. summary and comparison

although both acetic anhydride and acetic acid are acid derivatives, they are significantly different in molecular structure, physical properties, uses and chemical reaction characteristics. Understanding these differences helps professionals choose the right materials in actual production, optimize the process, and ensure production safety and environmental protection. Through in-depth analysis of their differences, we can better grasp the characteristics of these two compounds and provide strong support for technical applications in the chemical industry.