Lesson 0. Nitrate activity №1 Read the text and translate

LESSON 10.2

NITRATE

Activity № 1

Read the text and translate.

Nitrate is a polyatomic ion with the molecular formula NOS— and a molecular mass of 62.0049 g/mol. Nitrates also describe the organic functional group R0N02. These nitrate esters are a specialized class of explosives.The anion is the conjugate base of nitric acid, consisting of one central nitrogen atom surrounded by three identically bonded oxygen atoms in a trigonal planar arrangement. The nitrate ion carries a formal charge of -1. This results from a combination formal charge in which each of the three oxygens carries a -2/3 charge, whereas the nitrogen carries a +1 charge, all these adding up to formal charge of the polyatomic nitrate ion. This, arrangement is commonly used as an example of resonance. Like the isoelectronic carbonate ion, the nitrate ion can be represented by resonance structures:Almost all inorganic nitrate salts are soluble in water at standard temperature and pressure. A common example of an inorganic nitrate salt is potassium nitrate (saltpeter).Nitrate salts are found naturally on earth as large deposits, particularly of Chile saltpeter a major source of sodium nitrate.Nitrites are produced by a number of species of nitrifying bacteria, and the nitrate compounds for gunpowder (see this topic for more) were historically produced, in the absence of mineral nitrate sources, by means of various fermentation processes using urine and dung.Nitrates are mainly produced for use as fertilizers in agriculture because of their high solubility and biodegradability. The main nitrates are ammonium, sodium, potassium, and calcium salts. Several million kilograms are produced annually for this purpose.The second major application of nitrates as oxidizing agents, most notably in explosives where the rapid oxidation of carbon compounds liberates large volumes of gases (see Gunpowder for an example). Sodium nitrate is used to remove air bubbles from molten glass and some ceramics. Mixtures of the molten salt are used to harden some metals.Free nitrate ions in solution can be detected by a nitrate ion selective electrode. Such electrodes function analogously to the pH selective electrode. This response is partially described by the Nernst equation.Nitrate toxicosis can occur through enterohepatic metabolism of nitrate to nitrite being an intermediate. Nitrites oxidize the iron atoms in hemoglobin from ferrous iron (2+) to ferric iron (3+), rendering it unable to carry oxygen. This process can lead to generalized lack of oxygen in organ tissue and a dangerous condition called methemoglobinemia. Although nitrite converts to ammonia, if there is more nitrite than can be converted, the animal slowly suffers from a lack of oxygen.

Activity № 2

Work on Cluster.

Activity № 3

Answer the questions.

Activity № 4



Activity № 5

Botir va Sora o‘rtasidagi suhbatni o‘qing. Fe’llarni to‘g’ri shaklda qo‘ying.

Sora: Botir!How nice to see you! What (1)...............(you/do) these days?

Botir: I (2)....... (train) to be a supermarket manager.

Sora: Really? What's it like? (3)........(you/enjoy) it?

Botir: It's all right. What about you?

Sora: Well, actually I (4).............(not/work) at the moment. I (5)......(try) to find a

job but it's not easy. But I'm very busy. I (6)........(decorate) my flat.

Botir(7)........... (you/do) it alone?

Sora: No, some friends of mine (8)............ (help) me.

Control questions

1. How is the role of nitrogen in the soil?

2. Is there any nitrogen in water?

3. What will happen if there is a lack of nitrogen in the soil?

4. What is the formula of ammonia?

5.Is an animal manure useful for a plant?