Chemistry – Petroleum A Review
Name: ______________________________
For the quiz, be able to address these big ideas:
1. Many common materials are produced from starting materials that are derived from petroleum.
2. Petroleum is a nonrenewable resource that is used as both a source of starting materials for
plastics and other common items, as well as a fuel for heating and transportation. 84% of
petroleum is used as a fuel source.
3. Petroleum is a mixture of hydrocarbon compounds (petrochemicals) that needs to be “sorted” via
fractional distillation before they are processed further.
4. Alkanes are a class of petrochemicals that contain all single bonds connecting the carbon atoms.
They are named systematically and can be either branched or straight-chain connection of C
atoms.
5. Isomers are compounds with the same molecular formula, but different structural formulas.
6. Intermolecular attractions are forces that hold molecules together in a sample. The larger and
straighter the molecule is, the stronger the IMA’s and the higher the boiling point.
Practice questions. The answers to these questions are on the back of this page.
1. Name this compound:
2. There is another way to arrange the atoms in the molecule above…in other words there is another isomer
of this molecule. Draw it and then name it.
3. During fractional distillation, crude oil is heated up to 400 degrees Celsius and the molecules vaporize and
rise up the column. They cool down as they rise, and condense at different heights because they have
different ______________________.
4. How many electrons are found in this molecule:
5. Name this compound:
6. Write the molecular and structural formula for this compound: 2,5-dimethylhexane.
7. Is octane an isomer of the molecule in question 6 above? Explain.
8. Compare the IMA strength and boiling point of octane and 2,5-dimethylhexane.
Answers.
1. butane
2. methylpropane:
3. boiling points
4. 14 electrons – two in each bond.
5. 3-methylpentane
6. C8H18 ,
7. Yes, octane is an isomer, because they both have the molecular formula C8H18, but have different
structural formulas.
octane
2,5-dimethylhexane
8. Octane is the straight-chain isomer and 2,5-dimethylhexane is the branched isomer of C8H18. Octane will
have the higher boiling point and stronger IMA’s. When the molecule becomes branched, the strength of
attraction between the molecules weakens, and therefore the boiling point drops.