Lesson 4: Cracking/ Alkenes Flashcards
1
Q
What is the purpose of “cracking” long- chain hydrocarbons?
A
- Long- chain hydrocarbons can be cracked to prouce smaller, more useful molecules.
2
Q
What are the two different methods of cracking?
A
1.) Catalytic cracking.
2.) Steam cracking.
3
Q
What are the conditions of catalytic cracking?
A
- High temperature.
- Presence of a catalyst (to speed up the reaction.)
4
Q
What are the conditions of steam cracking?
A
- High temperature.
- Steam used.
5
Q
Which is more reactive?
Alkanes OR alkenes?
A
- Alkenes are more reactive than alkanes.
alkenes react with bromine water whereas, alkanes do not!
6
Q
What are the products of cracking?
A
Alkane + alkene.
7
Q
What is the test for alkenes?
A
- Bromine water goes from orange to COLOURLESS after reacting with an alkene.
Do not say bromine water is clear! It’s COLOURLESS!!
8
Q
Why are alkenes extremely useful?
Give 2 reasons
A
1.) Alkenes can be used to produce polymers.
2.) Alkenes can be used as starting materials for the production of many other chemicals.
9
Q
Why are some of the products of cracking useful?
A
- Small molecules/ short- chain hydrocarbons.
- So, are useful as fuels.
10
Q
Give 3 transport vehicles that all use hydrocarbons.
A
- Ships.
- Cars.
- Aeroplanes.
