1. Bromine is one of the elements. Bromine must be handled with extreme care.
2. They will increase their knowledge in chemistry. They will read a lot.
3. He will go to see his parents. His examp will be over.
4. The pharmacist gave me the drug. He advised me to keep it in a cool place.
VI. :
1. In what states can hydrocarbons occur?
2. What classification systems are developed to distinguish hydrocarbons?
3
3 :
1. :
) (the Active Voice) Present, Past, Future Perfect;
) (the Passive Voice) - Present, Past, Future Perfect;
2. :
) Infinitive (). .
) the Gerund(). . .
3. one, it, that .
. , . .
I ( . II)
This preparation has found
Wide use in the treatment of .
pneumonia in children.
has found Present Perfect Active to find.
II ( .V)
The plant (had been grown,
was grown, is been growing) under 10 -
fluorescent light for 10 h. . hd bn grown - st rfect ssive t grow
III ( .VI)
he best way to determine the
amount of material in a sample --
of a solid is to weight it on a balance. .
to determine -
to weigh - .
3
I. . 1,2,3,5 6 :
Carbohydrates.
1. Carbohydrates are compounds containing the elements of carbon, hydrogen and oxygen, the last
two elements being usually present in the proportions in which they are found in water. The group
includes sugars of different degrees of complexity and polysaccharides such as starch, inulin and cel-
lulose.
2. Sugars are readily soluble in water and in general, can be induced to crystallize only with duf -
ficulty and after careful purification.They have a sweet taste. Of the polysaccharides inulin is soluble
in warm water but the more complex cellulose is insoluble.
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3. All carbohydrates give a violet colour when treated with alphanaphtol followed by concentrated
sulphuric acid. The test may be applied either to a solution or in the case of an insoluble carbohyd-
rate to its suspension in water.
4. Some carbohydrates are reducing. Non-reducing carbohydrates such as sucrose and the polysac-
charides can be hydrolised by boiling for about half an hour or more with a little dilute acid. After
neutralizing them with an excess of caustic soda, it will be found that reducing sugars have been pro-
duced.
5. Pentose sugars when bolled with concentrated hydrochloric acid containing a little phlorogluci-
nol give a red colour.
The process of hydrolysis is a reversible one and more complex carbohydrates are synthesized in
the plant from sugar units.
6. In addition to the sugars referred to above there are some relatively rare desoxy sugars which
have so far only been found in nature in cardiac glycosides. These desoxy sugars contain one or two
oxygen atoms fewer than the corresponding carbohydrates with six carbon atoms. They include rham-
nose, digitoxose, and cymarose.
1. sugars... n be included to crystallize with difficulty - .
2. when treated with alphanaphtol - .
3. non-reducing - .
4. in addition to the sugars reffered to abov - , .
5. fewer - .
