Symbol N. Atomic Weight 14.008.

Occurrence. Nitrogen occur in the free state in air, of which it forms four-fifths by volume. Nitrogen exists in the state of combination in nitre or saltpetre, potassium nitrate, KNO₃. It forms an essential constituent of the bodies of all animals and plants.

     Properties of Nitrogen. Nitrogen is a colourless, transparent, tasteless and inodorous gas. It neither supports combustion, nor burns, Nitrogen does not only combine with oxygen readily, but it does not combine with any other element easily except at a very high temperature, Even such compound which it forms are unstable and easily decomposed.

     Nitrogen is slightly soluble in water, 1000 parts of water are able to dissolve 28 parts of the gas. By great cold and great pressure nitrogen is reduced to the liquid and even to the solid state. It has no action upon Litmus-paper, and since this fact indicates that it is neither acid nor alkaline. We must call nitrogen a neutral substance.

     Preparation. Nitrogen can be prepared by burning phosphorus in closed volume of air. Oxygen is entirely removed. After whit fumes of phosphorus pentoxide (P₂O₅) have disappeared, the colourless gas remaining is nearly pure nitrogen.

 

XIII. Read and translate the following one-root words:

nitrogenous, nitrate, nitrite, nitrous acid.

 

XIV. Find the sentences with the following word-combinations and translate them:

litmus paper, closed volume, an essential constituent, easily decomposed, in the state of combination, compound condition.

 

XV. Find the sentences with neither.....nor....; either....or and translate them into Russian.

XVI. Choose the correct form of the verb.

1. Nitrogen... in the free state in air.(occur, is occured)

2. Nitrogen... by burning phosphorus in a closed volume of air. (to prepare, is prepared)

3. Nitrogen... by heating one of its compounds. (is evolved, are evolved)

4. The hydrochloric acid... with excess of ammonia, forming salt-ammoniac. (unites, is united)

5. Active nitrogen... readily with any elements, including sulphur and phosphorus. (combines, is combined)

6. Plants and animals... nitrogen for their life and growth.(need, are needed)

 

 XVII. Insert the missing words.

1. Nitrogen... in the state of combination in nitre.

2. When phosphorus burns in a closed volume of air, oxygen is entirely...

3. Nitrogen forms an... constituent of all animal... bodies

4. If a concentrated solution of ammonium nitrite is heated, nitrogen is... and water is....

5. In the experiment with hydrochloric acid ammonia always remains is....

(eliminated, removed, essential, exist, vegetable, evolved, excess)

 

XVIII. Complete the sentences.

1. Nitrogen is a....

2. Nitrogen can be prepared....

3. Nitrogen gas can be obtained....

4. Nitrogen occurs in....

5. Ammonia consists of....

 

XIX. Translate the following sentences:

1. Большая часть азота находится в природе в свободном состоянии.

2. Почва содержит незначительные количества азота преимущественно в виде солей азотной кислоты.

3. Азот – бесцветный газ, не имеющий запаха и весьма мало растворимый в воде.

4. С водородом азот вступает во взаимодействие при высокой температуре и давлении в присутствии катализатора.

5. Название «азот» происходит от греческого слова «азоос», что значит «безжизненный».

6. Латинское название азота – «Nitrogenium».

 

XX. Divide the text into some parts and name them like the followings:

1. Occurrence of Nitrogen.

2. Properties of Nitrogen.

3. Preparation of Nitrogen.

XXI. Answer the following questions.

1. Does nitrogen occur in the free state in air?

2. What compounds does nitrogen exist in the state of combination in?

3. What element is an essential constituent of bodies of all animals and plants?

4. Which way can nitrogen be prepared?

5. What takes place, when a concentrated solution of ammonium nitrite is heated?

6. Does nitrogen have any colour, taste or odour?

7. What most important compounds of Nitrogen do you know?