Vocabulary. hydrolysis - гидролиз

ammonia - аммиак

pungent - едкий

alcohol - спирт

hydrolysis - гидролиз

ammonium nitrate - нитрат аммония

ammonium phosphate - фосфат аммония

urea - мочевина, карбамид

fertilizer - удобрение

explosive - взрывчатое вещество

dyestuff - краситель

resin - смола

moderate - усредненный

to permit - позволять

solvent - растворитель

combustion - горение

to contain - содержать

to nitrify - нитрифицировать

to yield - вызывать, приводить к образованию

bacterium (pl. bacteria) - бактерия

nitrogen-fixing bacteria - бактерии, связывающие азот

to give rise - приводить к образованию

to release - высвобождать

nitrogen cycle - азотный цикл

proton acceptor - акцептор протонов

Exercise 2. Answer the following questions.

1. Where is ammonia soluble?

2. What substance is liquid ammonia similar to?

3. How is ammonia made industrially?

4. What substances does ammonia give when it burns in air?

5. What are the major uses of ammonia?

Exercise 3. Put questions to the bold-typed words.

1. Ammonia may be prepared in the laboratory by reacting ammonium salts with bases.

2. Ammonia is a good proton acceptor.

3. In the presence of catalysts NO, NO₂ and water are formed.

4. Moderate dielectric constant permits ammonia to act as an ionizing solvent.

5. Ammonia is used in the manufacture of nitric acid.

6. Ammonia dissolves electropositive metals.

7. When burnt in air ammonia yields nitrogen and water.

Exercise 4. Match the definition with the correct word.

1. Chemical energy is a) a substance that causes a chemical

reaction to happen quickly.

2. Carbon monoxide is b) a process of using fuel to produce heat or

energy.

3. Commercial use means c) a poisonous gas produced by the engines

of vehicles.

4. Compound is d) an energy which is stored in fuels.

5. Catalyst is e) use in business.

6. Burning is f) a chemical substance that consists of two or

more elements that together form a molecule.

7. Potassium hydroxide is g) a white alkaline compound that is used,

for example, in soap manufacture.

Exercise 5. Give the synonyms for the following words and make up sentences with them: burning, to yield, amount, to give rise, to convert, important, to release, manufacture.

Exercise 6. Put the following words in the gaps: to contain, amount, vehicles, to release, pungent, fertilizers, bacteria.

1. We have obtained a large … of calcium oxide during this experiment.

2. This cheese has very … odour.

3. Ammonia … hydrogen and nitrogen.

4. Yesterday there were a lot of parked … near the theatre.

5.

When heating water solution ammonia gas ….

6. Our farmers usually use many … to make soil more fertile.

7. … exist in large quantities in air, water, dead creatures and plants.

Exercise 7. Make the following sentences interrogative and negative.

1. Liquid ammonia has some similarity to water.

2. Nitrogen - fixing bacteria are able to achieve the reactions which are similar to the reaction of the Haber process.

3. It also dissolves electropositive metals.

4. The combustion of ammonia in air yields nitrogen and water.

5. It is very soluble in water and soluble in alcohol.

6. Ammonia is a good proton acceptor.

Exercise 8.: Paraphrase the following expressions using attributive chain and translate them.

E.g.: the reduction of carbon – carbon reduction:

1. the technology of the production of fullerenes;

2. the production of soot;

3. the synthesis of vinyl acetate;

4. the pyrolysis of ethylene;

5. the technique of the determination of the content of soot particles;

6. the investigation of the rare earth oxides of terbium and praseodymium.;

7. the combustion of ammonia;

8. the modifications of electric field;

9. the solution of ammonia.

Texts for educational purposes

Synthesized and natural compounds of nitrogen

Amides are organic compounds containing the group -CO.NH₂ (the amide group). Compounds containing this group are primary amides. Secondary and tertiary amides can also exist, in which the hydrogen atoms on the nitrogen are replaced by one or two other organic groups respectively. Simple examples of primary amides are ethanamide, CH₃CONH₂, and propanamide, C₂H₅CONH₂. They are made by heating the ammonium salt of the corresponding carboxylic acid. Amides can also be made by reaction of ammonia (or an amine) with an acyl halide. Amides can also be defined as inorganic compounds containing the ion NH₂^-, e.g. KNH₂ and Cd(NH₂)₂. They are formed by the reaction of ammonia with electropositive metals.

Amination is a chemical reaction in which an amino group (-NH₂) is introduced into a molecule. Examples of amination reaction include the reaction of halogenated hydrocarbons with ammonia (high pressure and temperature) and the reduction of nitro- compounds and nitriles.

Amines are organic compounds derived by replacing one or more of the hydrogen atoms in ammonia by organic groups. Primary amines have one hydrogen replaced, e.g. methylamine, CH₃NH₂. They contain the functional group -NH₂ (the amino group). Secondary amines have two hydrogens replaced, e.g. methylethylamine, CH₃(C₂H₅)NH. Tertiary amines have all three hydrogens replaced, e.g. trimethylamine, (CH₃)₃N. Amines are produced by the decomposition of organic matter. They can be made by reducing nitro compounds or amides.

Amine salts are salts similar to ammonium salts in which the hydrogen atoms attached to the nitrogen are replaced by one or more organic groups. Amines readily form salts by reaction with acids, gaining a proton to form a positive ammonium ion. They are named as if they were substituted derivatives of ammonium compounds; for example, dimethylamine ((CH₃)₂NH) will react with hydrogen chloride to give dimethylammonium chloride, which is an ionic compound [(CH₃)₂NH₂]⁺ Cl^-. When the amine has a common nonsystematic name the suffix -ium can be used; for example, phenylamine (aniline) would give [C₆H₅NH₃]⁺ Cl^-, known as anilinium chloride. Formerly, such compounds were sometimes called hydrochlorides, e.g. aniline hydrochloride with the formula C₆H₅NH₂.HC1.

Salts formed by amines are crystalline substances that are readily soluble in water. Many insoluble alkaloids (e.g. quinine and atropine) are used medicinally in the form of soluble salts (hydrochlorides). If alkali (sodium hydroxide) is added to solutions of such salts the free amine is liberated. If all four hydrogen atoms of an ammonium salt are replaced by organic groups a quaternary ammonium compound is formed. Such compounds are made by reacting tertiary amines with halogen compounds; for example, trimethylamine ((CH₃)₃N) with chloromethane (CH₃C1) gives tetramethylammonium chloride, (CH₃)₄N⁺ Cl^-. Salts of this type do not liberate the free amine when alkali is added, and quaternary hydroxides (such as (CH₃)₄N⁺ OH^-) can be isolated. Such compounds are strong alkalis, comparable to sodium hydroxide.

Amino acid is any of a group of water-soluble organic compounds that possess both a carboxyl (-COOH) and an amino (-NH₂) group attached to the same carbon atom, called the a-carbon atom. Amino acids can be represented by the general formula R-CH(NH₂)COOH. R may be hydrogen or an organic group and determines the properties of any particular amino acid. Through the formation of peptide bonds, amino acids join together to form short chains (peptides) or much longer chains (polypeptides). Proteins are composed of various proportions of about 20 commonly occurring amino acids. The sequence of these amino acids in the protein polypeptides determines the shape, properties and hence biological role of the protein. Some amino acids that never occur in proteins are nevertheless important, e.g. ornithine and citrulline, which are intermediates in the urea cycle.

Plants and many microorganisms can synthesize amino acids from simple inorganic compounds, but animals rely on adequate supplies in their diet. The essential amino acids must be present in the diet whereas others can be manufactured from them.

On acids and their properties

Acid is a type of compound that contains hydrogen and dissociates in water to produce positive hydrogen ions. The reaction, for an acid HX, is commonly written

HX = H⁺ + X^-.

In fact, the hydrogen ion (the proton) is solvated and the complete reaction is:

HX + H₂O = H₃O⁺ + X^-.

The ion H₃O⁺ is the oxonium ion (or hydroxonium ion or hydronium ion). This definition of acids comes from the Arrhenius theory. Such acids tend to be corrosive substances with a sharp odor, which turn litmus red and give colour changes with other indicators. They are referred to protonic acids and are classified into strong acids, which are almost completely dissociated in water (e.g. sulphuric acid and hydrochloric acid) and weak acids, which are only partially dissociated (e.g. ethanoic acid and hydrogen sulphide). The strength of an acid depends on the extent to which it dissociates, and is measured by its dissociation constant. In the Lowry-Brensted theory of acids and bases (1923), the definition was extended to one in which an acid is a proton donor (Brensted acid) and a base is a proton acceptor (Brensted base). For example, in HCN + H₂O = H₃O⁺ + CN^-.

The HCN is an acid, in that it donates a proton to H₂O. The H₂O is acting as a base in accepting a proton. Similarly, in the reverse reaction H₃О⁺ is an acid and CN^- is a base. In such reactions, two species related by loss or gain of a proton are said to be conjugate. Thus, in the reaction above HCN is the conjugate acid of the base CN^- and CN^- is the conjugate base of the acid HCN. Similarly, H₃O⁺ is the conjugate acid of the base H₂O. An equilibrium, such as that above, is a competition for protons between an acid and its conjugate base. A strong acid has a weak conjugate base and vice versa. Under this definition water can act as both acid and base. Thus in

NH₃ + H₂O = NH₄⁺ + OH^- the H₂O is the conjugate acid of OH^-. The definition also extends the idea of acid-base reaction to solvents other than water. For instance, liquid ammonia, like water, has a high dielectric constant and is a good ionizing solvent. Equilibria of the type:

NH₃ + Na⁺Cl^- = NaNH₂ + HC1 can be studied, in which NH₃ and HC1 are acids and NH₂^- and CI^- are their conjugate bases.

A further extension of the idea of acids and bases was made in the Lewis theory (G. N. Lewis, 1923). Here a Lewis acid is a compound or atom that can accept a pair of electrons and a Lewis base is one that can donate an electron pair. This definition encompasses traditional acid-base reactions. In

HCl + NaOH = NaCl + H₂O

the reaction is essentially H⁺ +:OH^- = H:OH

i.e. donation of an electron pair by OH^-. But it also includes reactions that do not involve ions, e.g.

H₃N: + BC1₃ = H₃NBC1₃ in which NH₃ is the base (donor) and BC1₃ is the acid (acceptor). The Lewis theory establishes a relationship between acid-base reactions and oxidation-reduction reactions.

Acidic describes a compound that is an acid, a solution that has an excess of hydrogen ions and a compound that forms an acid when dissolved in water. Carbon dioxide, for example, is an acidic oxide.

Acidic hydrogen is a hydrogen atom in an acid that forms a positive ion when the acid dissociates.

Acid salt is a salt of a polybasic acid (i.e. an acid having two or more acidic hydrogens) in which not all the hydrogen atoms have been replaced by positive ions. For example, the dibasic acid carbonic acid (H₂CO₃) forms acid salts (hydrogencarbonates) containing the ion HCO₃^-. Some salts of monobasic acids are also known as acid salts. For instance, the compound of potassium hydrogendifluoride, KHF₂, contains the ion [F...H-F]^-, in which there is hydrogen bonding between the fluoride ion F^- and hydrogen fluoride molecule.

Acidimetry is a volumetric analysis using standard solutions of acids to determine the amount of base present.