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Name:
………………………….
Class:
Grade 9
Subject:
Petroleum and Synthetic Materials.
Objective: To identify processing techniques of petroleum.
Worksheet (7.1)
At start of the refinery process, petroleum (crude oil) is preheated to a temperature of 350-400oC, and
pumped in at base of the fractionating tower. As it boils the vapor passes up to the tower. Then petroleum
components condense at different levels where these components are collected into different fractions as
follows:
Fraction Refinery Gasoline naphtha Kerosene Light
Heavy Bitumen
gas
gas oil gas oil
( n)
1-4
5-10
8-12
10-16
14-20
20-30
> 30
Where n is the number of the carbon atoms in the hydrocarbon in the fraction.
Give the name of the process used in separating the hydrocarbon fractions.
Indicate physical property on which separation depends.
Classify the technique used in separation as physical or chemical process. Justify.
Identify:
- The fraction released at the bottom of the fractionating tower.
- The part of the fractionating tower, at which, gaseous fraction is released.
- Which fraction, Gasoline or Kerosene, condense at higher level of the tower.
After separating the alkanes, propene (C3H6) could be obtained from the naphtha fraction of petroleum
which is heated in the absence of air and the following reaction occurs:
C10H22 → 2C3H6 + X
a. Indicate the technique used to obtain propene & hydrocarbon (X) from the naphtha fraction.
Identify the family to which hydrocarbon X belongs.
Give the name and the possible structural formulas of the hydrocarbon X.
Cracking is the process where large hydrocarbon molecules are broken down into smaller molecules,
which are used as raw materials in chemical industry as well as combustibles.
The
cracking of a hexane molecule gives a propane molecule and a molecule of compound (A).
Give the condensed structural formulas for the compounds obtained in cracking of hexane.
Classify cracking as chemical or physical process. Justify.
Pick out from the text, the definition of cracking.
Some of the hydrocarbons obtained in the distillation of petroleum are of limited use. To make them
more useful, they are cracked to make smaller alkanes and alkenes which are widely used as solvents and
raw materials in chemical synthesis.
The cracking of an alkane (A) gives hexane (C6H14) and an alkene (P). The number of carbon atoms
in a molecule of alkene (P) is 3.
The equation of cracking of (A) is: (A) → C6H14 + (P)
Determine the number of C-atoms and the number of H-atoms in a molecule of alkane (A).
Write the structural formula (P) and indicate the type of bonds between its carbon atoms.
Pick out from the text, the role of cracking.
Petroleum does not contain alkenes. Alkenes are prepared in chemical industry by catalytic cracking.
The cracking of heptane allows obtaining an alkene A containing 2 atoms of carbon per molecule and an
alkane B.
Write the equation for the cracking of heptane.
Give the name and write the condensed structural formula A and B.
Write the equation of polymerization of Alkene A and give the name of the polymer.
Worksheet in Chemistry / Prepared by: T. Wissam Abdallah