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Reactions of Amines

Pearson
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Ammonia, NH3, is a compound containing a nitrogen atom, with one lone pair of electrons and three single bonds to hydrogen atoms. Amines are derivatives of ammonia in which one or more of the hydrogens are replaced with other groups. In each derivative, the hydrogen is replaced by an alkyl or aromatic group, so a primary amine would have the nitrogen atom bonded to one alkyl or aromatic group; a secondary amine would have the nitrogen bonded to two alkyl or aromatic groups; and a tertiary amine would have three alkyl or aromatic groups bonded to the nitrogen atom. In acid-base chemistry, ammonia acts as a Brønsted-Lowry base by accepting a proton from water (H+) to produce an ammonium ion (NH4+) and a hydroxide ion (OH-). Like ammonia, amines are also Brønsted-Lowry bases, because the lone pair of electrons on the nitrogen atom accepts an H+ from water, producing a positively charged alkylammonium ion and a negatively charged hydroxide ion. The organic product is named by adding ammonium ion to the name of its alkyl group. Dimethylamine accepts an H+ to form dimethylammonium ion. Identify the balanced chemical equation for the reaction of diethylamine with water. Is it a, b, c or d? The correct answer is (b). Diethylamine has two ethyl groups and a hydrogen atom connected to the nitrogen atom. When diethylamine accepts an H+ from water, the product is the diethylammonium ion and hydroxide ion. The fishy odor detected in fish is sometimes due to amines, including trimethylamine. When you squeeze lemon juice on fish, the fishy odor is removed by converting the amines to their ammonium salts. Ammonium salts, like most salts, are solids at room temperature, and are odorless. Lemon juice contains the weak acid, citric acid, depicted here as the general weak acid, HA. In a neutralization reaction, an amine, such as trimethylamine, acts as a base and accepts an H+ from a generic acid, HA, or an acid such as citric acid, to form an ammonium salt. Identify the product of the reaction between N ,N-dimethylaniline and HCl. Is it a, b, c or d? The correct answer is (d). This reaction produces a salt. The nitrogen atom accepts an H+ from the acid to give a nitrogen with four groups bonded to it. The counterion to the resulting positive charge is the chloride ion. Ammonium salts, such as trimethylammonium chloride, are ionic compounds with strong attractions between the positively charged ammonium ion and an anion, often chloride. Like most salts, ammonium salts are solid at room temperature, odorless, and soluble in water and body fluids. For this reason, amines used as drugs are usually converted to their ammonium salts, which are soluble in water and body fluids. The ammonium salt of ephedrine is used as a bronchodilator and in decongestant products such as Sudafed. The ammonium salt of diphenhydramine is used in products such as Benadryl for relief of itching and pain from skin irritations and rashes. When an ammonium salt reacts with a strong base, such as NaOH, it is converted back to the amine, which is also called the free amine or free base. In this example, trimethylammonium chloride reacts with sodium hydroxide to form the free amine, trimethylamine, and sodium chloride and water. Identify the common name for the amine that results from the reaction of this ammonium salt, a secondary ammonium chloride with one methyl group, one ethyl group, and two hydrogens on the nitrogen, with NaOH. Is it a, b, c or d? The correct answer is (a). The reaction of the salt ethylmethylammonium chloride with the strong base NaOH gives the free amine, ethylmethylamine, sodium chloride, and water.
Ammonia, NH3, is a compound containing a nitrogen atom, with one lone pair of electrons and three single bonds to hydrogen atoms. Amines are derivatives of ammonia in which one or more of the hydrogens are replaced with other groups. In each derivative, the hydrogen is replaced by an alkyl or aromatic group, so a primary amine would have the nitrogen atom bonded to one alkyl or aromatic group; a secondary amine would have the nitrogen bonded to two alkyl or aromatic groups; and a tertiary amine would have three alkyl or aromatic groups bonded to the nitrogen atom. In acid-base chemistry, ammonia acts as a Brønsted-Lowry base by accepting a proton from water (H+) to produce an ammonium ion (NH4+) and a hydroxide ion (OH-). Like ammonia, amines are also Brønsted-Lowry bases, because the lone pair of electrons on the nitrogen atom accepts an H+ from water, producing a positively charged alkylammonium ion and a negatively charged hydroxide ion. The organic product is named by adding ammonium ion to the name of its alkyl group. Dimethylamine accepts an H+ to form dimethylammonium ion. Identify the balanced chemical equation for the reaction of diethylamine with water. Is it a, b, c or d? The correct answer is (b). Diethylamine has two ethyl groups and a hydrogen atom connected to the nitrogen atom. When diethylamine accepts an H+ from water, the product is the diethylammonium ion and hydroxide ion. The fishy odor detected in fish is sometimes due to amines, including trimethylamine. When you squeeze lemon juice on fish, the fishy odor is removed by converting the amines to their ammonium salts. Ammonium salts, like most salts, are solids at room temperature, and are odorless. Lemon juice contains the weak acid, citric acid, depicted here as the general weak acid, HA. In a neutralization reaction, an amine, such as trimethylamine, acts as a base and accepts an H+ from a generic acid, HA, or an acid such as citric acid, to form an ammonium salt. Identify the product of the reaction between N ,N-dimethylaniline and HCl. Is it a, b, c or d? The correct answer is (d). This reaction produces a salt. The nitrogen atom accepts an H+ from the acid to give a nitrogen with four groups bonded to it. The counterion to the resulting positive charge is the chloride ion. Ammonium salts, such as trimethylammonium chloride, are ionic compounds with strong attractions between the positively charged ammonium ion and an anion, often chloride. Like most salts, ammonium salts are solid at room temperature, odorless, and soluble in water and body fluids. For this reason, amines used as drugs are usually converted to their ammonium salts, which are soluble in water and body fluids. The ammonium salt of ephedrine is used as a bronchodilator and in decongestant products such as Sudafed. The ammonium salt of diphenhydramine is used in products such as Benadryl for relief of itching and pain from skin irritations and rashes. When an ammonium salt reacts with a strong base, such as NaOH, it is converted back to the amine, which is also called the free amine or free base. In this example, trimethylammonium chloride reacts with sodium hydroxide to form the free amine, trimethylamine, and sodium chloride and water. Identify the common name for the amine that results from the reaction of this ammonium salt, a secondary ammonium chloride with one methyl group, one ethyl group, and two hydrogens on the nitrogen, with NaOH. Is it a, b, c or d? The correct answer is (a). The reaction of the salt ethylmethylammonium chloride with the strong base NaOH gives the free amine, ethylmethylamine, sodium chloride, and water.