Topic 14 - Hydrocarbons Flashcards
What are hydrocarbons made of?
Hydrogen and Carbon only.
What are alkanes?
Saturated hydrocarbons.
What does saturated mean?
No double bonds. Each Carbon atom is bonded 4 times with the max no. of Hydrogens possible.
What is the general formula for alkanes?
C(n) H(2n + 2)
What is the general formula for cycloalkanes?
C(n) H(2n)
What are cycloalkanes?
A functional group isomer of alkanes.
Where are alkanes found?
Crude oil.
What is crude oil?
A mixture of different length hydrocarbons.
How are alkanes in crude oil separated?
Fractional distillation.
Where do alkanes with the highest boiling point condense in fractional distillation?
At the bottom of the column.
Where do the shortest hydrocarbons condense?
At the top. Some may not even condense and be taken off the top as a gas.
Why do alkanes condense at different temperatures?
Different lengths and different boiling points.
How can gas from fractional distillation be used?
LPG and stove gas.
How can petrol from fractional distillation be used?
Petrol cars.
How can diesel from fractional distillation be used?
Diesel cars.
How can fuel oil from fractional distillation be used?
Ships and power stations.
How can kerosine from fractional distillation be used?
Jet fuel and heating.
How can bitumen from fractional distillation be used?
Roofing and tarmac.
Which fractions are more valuable and useful?
Lighter fractions.
How can more lighter fractions be made?
Cracking.
Heavier fractions can be cracked to higher demand lighter fractions.
What is cracking?
Breaking a longer chain alkane into shorter hydrocarbons.
What are the two types of cracking?
Thermal and catalytic.
What are the conditions for thermal cracking?
1000* C
70 atm
What are the products of thermal cracking?
Mainly alkenes.