Distinguishing Ethanol Acetaldehyde Acetate Propylamine

In the chemical industry, it is very important to distinguish between different organic compounds. Among them, ethanol, acetaldehyde and propylamine acetate are three common organic compounds, but they have significant differences in molecular structure, physical properties and chemical properties. This article will analyze in detail how to distinguish these three substances from the three aspects of molecular structure, physical properties and chemical properties.

1. molecular structure analysis

1. Molecular structure of ethanol Ethanol (C₂ H∞OH) is an alcohol containing hydroxyl (-OH). Its molecular structure is formed by the replacement of a hydrogen atom in an ethane molecule (C₂ H� 6) with a hydroxyl group. Ethanol has two carbon atoms in the molecule, one of which is connected to a hydrogen atom and a hydroxyl group, and the other is connected to two hydrogen atoms and a methyl group (-CH). Ethanol molecules have enantiomers, but because of their smaller molecular weight, they have fewer isomers.

2. Molecular structure of acetaldehyde Acetaldehyde (CHYCHO) is an organic compound containing an aldehyde group (-CHO). Its molecular structure consists of a methyl group (-CH� 3) connected to an aldehyde group (-CHO). One carbon atom of the acetaldehyde molecule is connected to two hydrogen atoms, and the other carbon atom is connected to a double bond (= O) and a methyl group (-CH3). Acetaldehyde has no isomers and therefore has a single structure.

3. Molecular structure of propylamine acetate Propylamine acetate (CHY3 CONHCHY3) is an organic compound containing an amide group (-CONH-). Its molecular structure is formed by a transesterification reaction of acetic acid (CHYCOOH) and a methanamine (NHCH3). Propylamine acetate has one carbon atom attached to two methane (CH3) groups, one carbon atom attached to a carbonyl (C = O) group, and one amino (NH) group.

Through the analysis of molecular structure, it can be seen that ethanol, acetaldehyde and propylamine acetate have significant differences in functional groups and connection methods, which is the key to distinguish them.

2. physical property analysis

1. Boiling Point Ethanol has a boiling point of 78.3°C, acetaldehyde has a boiling point of 63.1°C, and propylamine acetate has a boiling point of 166.6°C. The difference in boiling point is mainly determined by the intermolecular forces, the intermolecular forces of ethanol and acetaldehyde are small, and the intermolecular forces of propylamine acetate are large, so the boiling point is higher.

2. Density Ethanol has a density of 0.789g/cm3, acetaldehyde has a density of 1.001g/cm3 and propylamine acetate has a density of 0.863g/cm3. The difference in density is mainly determined by the molecular structure and molecular weight.

3. Color and smell Ethanol is a colorless liquid at room temperature, light red; acetaldehyde is a colorless gas at room temperature, with a slight pungent odor; propylamine acetate is a colorless liquid at room temperature, with a pungent odor. The difference in smell can help distinguish the three substances.

3. chemical properties analysis

reaction characteristics of
1. Ethanol is easily hydrolyzed to acetic acid and ethanol under acidic conditions, and easily oxidized to acetaldehyde under alkaline conditions. Acetaldehyde is easily oxidized to acetic acid under acidic conditions, and easily reacts with aldehyde groups to form other products under basic conditions. Propylamine acetate reacts readily with carboxylic acids to form esters under acidic conditions and with alcohols to form ethers under basic conditions.

Through the analysis of the reaction characteristics, it can be seen that there are significant differences in the behavior of ethanol, acetaldehyde and propylamine acetate in the chemical reaction, which is another important basis for distinguishing them.

4. how to choose the identification method?

Based on the above analysis, the following methods can be used to distinguish ethanol, acetaldehyde and propylamine acetate:

1. 
   of physical property detection These three substances can be distinguished by measuring boiling point, density and odor.
Molecular Structure Analysis of
2. 
   The molecular structure of ethanol, acetaldehyde and propylamine acetate can be distinguished by infrared spectroscopy.
3. 
   of Chemical Reaction Experiment The reaction characteristics of different substances can be observed by chemical reactions under acidic or basic conditions.

5. summary

Through molecular structure analysis, physical properties analysis and chemical properties analysis, we can clearly see the differences in structure, physical properties and chemical reactions of ethanol, acetaldehyde and propylamine acetate. These three substances have a wide range of applications in industry and life, so it is very important to distinguish them. Through the above analysis, readers can better grasp how to distinguish these three substances.