3 Part One. The Predicate

Section II
Mashq 1. Ushbu matnni o’qing 4 В. Ko’rib chiqing va qisqacha aytib bering.
Mashq 2. а) Quyidagi xalqaro so’zlar nimani anglatadi?:

essential, respiration, process, diatomic, litre, atmosphere, crystalline, laboratory, accelerate, distillation, control, condition, cylinder, electrolysis, condense

b) Quyidagilar qanday elementlar: potassium, chlorine, manganese, nitrogen, hydrogen
Mashq 3. Tanlangan so’zlarning ma’nosini vaziyati bo’yicha aniqlang.
1. Water is a compound with the formula H₂O. 2. Oxygen supports combustion. 3. A gas which has no colour and odour is called colourless and odourless. 4. One litre of water at 0eC dissolves 48.9 ml of oxygen gas at Uatm pressure. 5. The boiling point of water is 100°C. 6. Water freezes at 0°C. 7. Above 0°C water is liquid and below 0°C it is solid. 8. Heating potassium chlorate is followed by the evolution of oxygen. 9. When water is boiling, it is evaporating. 10. Oxygen is stored in steel cylinders. 11. When the reaction proceeds very quickly, We usually say that its rate is high. 12. In the laboratory oxygen is obtained by heating KClO₃, and commercially it is made by the distillation of liquid air. 13. Oxygen is soluble in water very little.
Tekstga so’zlar:

fire — olov; odour — hid; pale — rangi o’chgan; melt — erimoq; amount— miqdor; volatile— летучий; tend— moyil

Text 4 В

Matnni o’qing (o’qish vaqti — 5 daqiqa).

Oxygen
Oxygen is one of the most abundant elements. It forms 21 percent of the atmosphere, 89 per ccnt of the water, and about SO per ccnt of the earth’s crust. Without oxygen, life cannot exist, as well as fire. Oxygen is essential in supporting respiration and combustion, it is used in many modern industrial processes. The element consists of diatomic molecules.

It is a colourless, odourless gas, which is slightly soluble in water: 1 litre of water at 0° dissolves 48.9 ml of oxygen gas at I -atm pressure. Its density at 0°C and 1 atm is 1.429 g litre*1. Oxygen condenses to a pale blue liquid at its boiling point, -183.0°C, and on further cooling freezes at -218.4°C to a pale blue crystalline solid.

Oxygen is easily prepared in the laboratory by heating potassium chlorate,

KClO₃: 2KClO₃ → 2KC1 + 3O₂ (g).

The reaction proceeds at a temperature just above the melting point of potassium chlorate if a small amount of manganese dioxide, MnO₂, is mixed with it. Although the manganese dioxide accelerates the rate of evolution of oxygen from the potassium chlorate, it itself is not changed.

Oxygen is made commercially mainly by the distillation of liquid air. Nitrogen is more volatile than oxygen, and tends to evaporate first from liquid air. Nearly pure oxygen is obtained by properly controlling the conditions of the evaporation. Oxygen is stored and shipped in steel cylinders, at pressures of 100 atm or more. Oxygen is also made commercially, together with hydrogen, by the electrolysis of water.

Mashq 4. Menga matnlardagi farqni ayting 4 В , 4 А.
Mashq 5. Matnni tematik bo’limlarga ajrating va har bir qism sarlavhasini qo’ying.
Mashq 6. Matn nima haqida ekanligini ayting:

1) о распространении кислорода; 2) о его физических свойствах; 3) о получении кислорода в лаборатории; 4) о промышленном получении кислорода; 5) о его хранении.

Mashq 7. Найдите в тексте и переведите на русский язык все предложения, в которых говорится о получении кислорода в промышленности.