Practice

Translate the following sentences paying attention to the verbs «would» and «should»

1. The halobenzenes should form a number of compounds.

2. He would test the device before putting it into service.

3. One should take this catalyst, not the old one.

4. Microwave determination dipole moments should be of a considerable reliance.

5. The temperature of the solution should be controlled.

6. It should be emphasized that the double bonds in the benzene ring are of inert character.

7. Viscosity would be expected to increase with intermolecular forces.

8. Should the value of p for ammonium ion be chosen as four or one ?

9. Expansion of solution would account only for 0.5 % change.

10. It would be highly desirable to have quantitative data involving kinetically controlled reactions.

11. This device should be tested.

12. These reactions would take place at high temperatures.

13. To understand this phenomenon you should get acquainted with the previous works devoted to this theme.

14. 6

    You should be very careful when you work with these reagents.

15. The instrument using such an element would not respond to the relative humidity.

16. Air saturated with water vapour at the temperature of 58^o F would contain 0.01 pound of water vapour per pound of dry air.

Part 2

Exercises 1. Read, translate and retell the text.

Carbon

Carbon is a non-metallic element that belongs to group 14 (formerly IV B) of the periodic table. Atomic number (a.n) is 6, relative atomic mass (r.a.m) is 12.011, melting point (m.p.) is ~ 3550^o C, boiling point (b.p.) is ~ 4827^oC. Carbon has three main allotropic forms.

Diamond occurs naturally and can be produced synthetically. It is extremely hard. The hardness of diamond results from the covalent crystal structure in which each carbon atom is linked by covalent bonds to four others that are situated at the corners of tetrahedron.

Graphite is a soft black slippery substance. It occurs naturally and can be produced by Acheson process. In graphite carbon atoms are arranged in layers where each carbon atom is surrounded by three others. The layers are held together by weak van der Waals’ forces. Graphite is a good conductor of heat and electricity. It has variety of uses including electrical contacts, high-temperature equipment and solid lubricants. Graphite mixed with clay is the ‘lead’ in pencils. The third crystalline allotrope is fullerite.

There are several amorphous forms of carbon: carbon black and charcoal. There are two stable isotopes of carbon (proton numbers 12 and 13) and four radioactive isotopes (10, 11, 14, 15). Carbon -14 is used in carbon dating.

Carbon occurs in all organic compounds. So carbon is fundamental to the structure of all living organisms. It is an essential element for plants and animals. It is ultimately derived from atmospheric carbon dioxide. It is assimilated by plants during photosynthesis.

Carbon forms a large number of compounds due to its unique ability to form stable covalent bonds with other carbon atoms and with hydrogen, oxygen, nitrogen and sulfur atoms.

Also there is a phenomenon in chemistry that is closely connected with carbon. It is carbon assimilation. Carbon assimilation is the incorporation of carbon from atmospheric carbon dioxide into organic molecules. This process occurs during photosynthesis.