Санкт-петербургского государственного университета высшее профессиональное образование т. А. Степанова, И. Ю. Ступина
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| Scction II
Упр. 1. Прочтите заглавие текста 11 В. Скажите, чему будет посвя щен этот текст? Что вы об этом знаете? Упр. 2. Назовите значения следующих интернациональных слов: modification, allotropic, violent, regular, amorphous, action, catalyze, separate, crystallization, distillation, condense, disulphidc, spontaneously Упр. 3. Определите значения выделенных слов по контексту. Сино нимы в скобках помогут вам. 1. As to the properties of phosphorus, they are very interesting. 2. Phosphorus ignites (takes fire) in the air at the temperature of 30 degrees. 3. Substances that easily take fire arc callcd inflammable substances. 4. A pressure of 760 mm Hg is callcd normal atmospheric pressure. 5. Phosphorus combines readily (easily) with oxygen. 6. Some reactions can be catalyzed by traces (very small amounts) of substances. 7. Opinions (points of view) concerning this problem differ. 8. Reduction is a proccss when a pure substance is obtained from an oxide. 9. It is difficult to realize (understand) that yellow and red phosphorus arc the same element. 10. A very finely divided substance is a powder. 11. Red phosphorus can be prepared by heating yellow phosphorus in the absence of air (without air). Слова к тексту: trace — прослеживать; partially — частично; careful — осторожный; drum — барабан; vaporize — испаряться; pretty — хорошенький, прелест ный; dangerous — опасный; dispose of — избавляться от Text 11 В Прочтите текст про себя (контрольное время чтения — 5 минут). Modifications of Phosphorus Yellow Phosphorus. Phosphorus may occur in three allotropic forms; yellow, violet, and black. However, the two most common forms arc yellow and red. There can be traced a difference of opinion as to whether the red form is a separate allotropic modification. One of the latest theories is that red phosphorus might be phosphorus only partially changed from the yellow to the violet form. The phosphorus obtained by the reduction of phosphorus is always the yellow variety. This is “regular” phosphorus and the other allotropic forms can be prepared from it. Phosphorus is able to combine readily with oxygen and ignite in the air at 30 degrees. Phosphorus is very soluble in carbon disulphidc. 82 Be very carcful with the phosphorus solution, as it is highly inflam mable. Dispose of it immediately after experimenting either by burning it or washing it down the drum with large quantities of water. Red phosphorus is so unlike yellow phosphorus, that it is difficult to realize that both forms arc the same element. The red type is an amorphous powder. It will not ignite spontaneously. It will not dissolve in carbon disulphidc. It will not glow in the dark. It has no odour and is not poisonous. It ignites only when it is heated to about 240 degrees. Red phosphorus can be prepared by heating yellow phosphorus in the abscncc of air. The action may be catalyzed by a trace of iodine. Violet phosphorus can be prepared by dissolving phosphorus in molten lead and then allowing it to separate by crystallization. Black phosphorus could be made by subjecting yellow or red phos phorus to 4,000 atmospheres of pressure at a high temperature. The yellow phosphorus can be prepared from any other form by distillation. When they are heated strongly enough, all forms of phosphorus vaporize and this vapour always condenses to form the yellow variety. Remember— phosphorus is like a pretty girl: always interesting, but sometimes dangerous! Упр. 4. Что нопого вам далось узнать из текста 11 В по сравнению с текстом 11 А? Упр. 5. Текст имеет подзаголовки. Выделите основную мысль каж дого отрывка, имеющего подзаголовок. Упр. б. Скажите, что говорится в тексте: 1) об аллотропных формах фосфора; 2) о фосфоре, полученном ме тодом восстановления; 3) о том, что представляет собой красный фос фор; 4) о способе получения черного фосфора; 5) о способе получения желтого фосфора. Упр. 7. Найдите в тексте предложения, касающиеся соблюдения ос торожности при работе с фосфором н переведите их на русский язык. жүктеу/скачать 5,96 Mb. Достарыңызбен бөлісу:
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