Preparation of Acetanilide
Learning Activity 1
Preparation of Acetanilide
Abstract
Recrystallization is a common method of purifying organic substances through the difference in solubility at different temperature. In this experiment, acetanilide was produced by acetylation of aniline with acetic anhydride. The crude acetanilide was dissolved in a solvent in a heating water bath. The solution was cooled slowly in an ice bath as crystals form out. As the compound crystallizes from the solution, molecules of other compounds dissolved in solution are excluded from growing crystal lattice, yielding pure acetanilide. Acetanilide is slightly soluble in water, and stable under most conditions. Pure crystals are plate shaped and colorless to white. This experiment involves four functional groups common in organic chemistry. Solids prepared in this manner serve a derivative, whose melting point may be correlated with known values and thus is a means of identification and serves as a test for homogeneity or purity.
I. Introduction
Acetic anhydride is a colorless liquid with a pungent vinegar-like odor when it reacts with water to form acetic acid. The boiling point of acetic anhydride is 140°C and the melting point is -73°C. It is soluble in ether, chloroform and benzene. It is soluble in water when acetic anhydride decomposes. The density of acetic anhydride is 1.082 g/ml in liquid state and its molecular weight is 102.09 g/mol. Acetic anhydride is most widely used for the conversion of cellulose to cellulose acetate, which is a component of photographic film and other coated materials. It plays an important role in the acetylation of aniline to form acetanilide. Acetanilide is in the general category of organic chemicals, since its main element is carbon. More specifically, it is an amide since it contains a carbon double bonded to an oxygen atom, while that same carbon is also connected to a nitrogen atom. It is also classified as an aromatic compound because the six carbon
Preparation of Acetanilide
Abstract
Recrystallization is a common method of purifying organic substances through the difference in solubility at different temperature. In this experiment, acetanilide was produced by acetylation of aniline with acetic anhydride. The crude acetanilide was dissolved in a solvent in a heating water bath. The solution was cooled slowly in an ice bath as crystals form out. As the compound crystallizes from the solution, molecules of other compounds dissolved in solution are excluded from growing crystal lattice, yielding pure acetanilide. Acetanilide is slightly soluble in water, and stable under most conditions. Pure crystals are plate shaped and colorless to white. This experiment involves four functional groups common in organic chemistry. Solids prepared in this manner serve a derivative, whose melting point may be correlated with known values and thus is a means of identification and serves as a test for homogeneity or purity.
I. Introduction
Acetic anhydride is a colorless liquid with a pungent vinegar-like odor when it reacts with water to form acetic acid. The boiling point of acetic anhydride is 140°C and the melting point is -73°C. It is soluble in ether, chloroform and benzene. It is soluble in water when acetic anhydride decomposes. The density of acetic anhydride is 1.082 g/ml in liquid state and its molecular weight is 102.09 g/mol. Acetic anhydride is most widely used for the conversion of cellulose to cellulose acetate, which is a component of photographic film and other coated materials. It plays an important role in the acetylation of aniline to form acetanilide. Acetanilide is in the general category of organic chemicals, since its main element is carbon. More specifically, it is an amide since it contains a carbon double bonded to an oxygen atom, while that same carbon is also connected to a nitrogen atom. It is also classified as an aromatic compound because the six carbon
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