The method of distinguishing styrene from styrene

1. Definition and Structure

Styrene (C? H?): Styrene is a carbon diene with a molecular structure of a benzene ring connected to a vinyl group. Its molecular formula is C, H, molecular weight of 104.14g/mol. There are two double bonds in the styrene molecule, which has a high degree of unsaturation.

Benzene ethylbenzene (Cfb): Benzene ethylbenzene is formed by the double bond of benzene and ethylene. Its molecular formula is CFSC, and its molecular weight is 132.18g/mol. Phenylethylbenzene has only one double bond in the molecule and has a low degree of unsaturation.

2. Physical Properties Comparison

1. Boiling Point: The boiling point of styrene is 105°C, while the boiling point of ethylbenzene is 149°C. The boiling point of ethylbenzene is higher, which indicates that the intermolecular force is stronger, which may be related to the molecular weight and structure.

2. Density: Styrene has a density of 1.096g/cm³, while ethylbenzene has a density of 1.052g/cm³. The high density of styrene may be related to the number and molecular structure of its double bonds.

3. Solubility: styrene is slightly soluble in water and easily soluble in organic solvents. Benzene is slightly soluble in water and has good solubility in organic solvents.

Dalton Law

Comparison and application of styrene and ethyl benzene:

• In the separation and purification process, according to their boiling point and density difference, using distillation, fractionation and other methods for separation.
• Industrially, styrene is commonly used in the production of polyethylene and other plastic materials, while benzene is used to make benzene acetic acid and other chemical intermediates.

3. Chemical Properties Comparison

1. Chemical reaction activity: styrene has high double bond activity and is easy to participate in addition and polymerization reactions. The double bond activity of benzene ethyl benzene is low, and the reaction is relatively slow.

2. Stability: Styrene has high chemical stability and is not easy to decompose. Benzene is also stable, but due to the larger molecular weight, the possibility of decomposition reaction is slightly higher.

4. industrial applications

1. Styrene application:

• Commonly used in the manufacture of polyethylene (HDPE, LDPE).
• In plastic, rubber and other materials production also has important applications.

1. benzene ethylbenzene application

• Commonly used in the manufacture of phenylacetic acid, benzene ethanol and other chemical products.
• In the pharmaceutical and dye industries also have important uses.

5. identification method

1. Physical identification:

• Through the distillation experiment, observe the two substances of the boiling point difference, the first evaporated is styrene (boiling point is lower).
• Through the density test, the use of hydrometer measured both density values.

1. Chemical identification:

• The addition reaction test is carried out to observe which substance is more prone to the addition reaction.
• A polymerization test was conducted to observe which substances under specific conditions decompose more significantly.

6. selection recommendations

In practical applications, the choice of styrene or ethylbenzene needs to consider the following factors:

• Molecular weight: benzene ethyl benzene molecular weight is larger, so that in industrial applications have certain advantages, but also bring higher costs.
• Use: according to the specific production needs, choose its use to match the material.
• Physical and chemical properties: according to the separation, purification and reaction of the specific requirements, select the appropriate material.

Styrene and ethylbenzene have significant differences in molecular structure, which are not only reflected in physical properties, but also profoundly affect their chemical applications. Chemical workers in the actual production, should choose the appropriate material according to the demand, in order to achieve the best production effect.