Summary
Summary Notes 3.3.2 - Alkanes
- Module
- Unit 3.3.2 - Alkanes
- Institution
- AQA
Summary Notes 3.3.2 - Alkanes
[Show more]
Seller
Follow
Content preview
Taylor’s Notes AlkanesGeneral Alkanes
Alkanes are hydrocarbon which are compounds which contain only carbon and hydrogen
They are called saturated because they contain no carbon-to-carbon double bonds, and so cannot undergo
addition reactions
They have the general formula CnH2n+2
Physical Properties of Alkanes
Boiling point of alkanes increases with the number of carbon atoms in a row in the chain because there is
greater surface area overlap with an increased carbon chain, therefore dispersion forces are stronger
Structural Isomers of Alkanes
Structural Isomers of Hexane (Skeletal Formula)
How is Crude Oil Separated?
Fractional Distillation
Vaporise the crude oil at 400°C
Put into fractionating column
There is a temperature gradient (bottom is hotter than the top)
Fractions have a different boiling point
Different fractions will condense at different heights and therefore separate
How do we know fractions are mixtures?
Fractions have a range of Boiling Points A pure substance has a single boiling point
Catalytic Cracking
Catalytic cracking requires a temperature of 500°C with a zeolite catalyst
Catalytic cracking is done as there is a higher demand for shorter chain hydrocarbons
Zeolite catalysts are used to favour the formation of short chain (branched) alkanes for motor fuels The
mechanism proceeds via carbocationic intermediates
Thermal Cracking
Thermal cracking requires 70atm and 450-750°C This mechanism proceeds via free radical intermediates
and produces a higher percentage of alkenes
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Taylorsnotes. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £4.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
53249 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now