Crude oil is a complex mixture of mainly alkanes ranging from C1 to C70. To give useful products, crude oil has to be refined first. It is usually separated into fractions shown in the table below:
Fraction
Number of carbon atoms per molecule
1
1-4
2
5-10
3
10-14
4
14-25
The residue
over 25
(a) Name fractions 1-4.
(b) An alkane with 18 carbon atoms or more is a solid. Explain why crude oil is a liquid though it contains many higher alkanes.
(c) We can use fraction 3 to kill mosquito larvae by spraying it on surface of ponds or stagnant water. Why can fraction 3 be used for such a purpose?
Chem question
2010-05-01 11:37 pm
回答 (2)
2010-05-02 12:51 am
✔ 最佳答案
1)Fracrtion 1: Refinary Gas/Petroleum gas2:petrol/kerosene
3:diseal
4:heavy oil
b)The liquid component of the crude oil can act as a solvent for other component of the crude oil. Therefore, the solid and gas alkane will dissolve in the liquid alkane in crude oil and the mixture of them appear as a liquid.
c)The fraction 3 of the crude oil will form a layer of oil on the surface of the water after spraying. The oil layer will prevent oxygen enter the water hence suffocate the mosquito larvae in the water
2010-05-05 9:30 pm
收錄日期: 2021-04-23 18:24:40
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