Summary
A level organic chemistry 9701 summary notes on Alkane, Alkenes and Benzene
- Course
- Institution
Contains all the reactions, definitions and notes needed for topic Alkanes, Alkenes and Benzene for organic chemistry 9701 syllabus.
[Show more]
Seller
Follow
Alevelnotez
Content preview
Organic Chemistry: Alkenes, Benzene & AlkanesChemistry
, Organic Chemistry |Alkenes, Benzene, Alkanes |Chemistry
Alkenes
General Formula: C n H 2 n
Ending: ene
Functional group: C = C
Unsaturated hydrocarbons: they can still have hydrogen atoms added to their formula.
Contain a carbon – carbon double bond somewhere in their structure.
Example 1: Name of Alkenes
Example 2: Skeletal formula of two isomers of C4H8 which are not alkene.
Physical Properties of Alkenes
1. Boiling Point
The boiling points of the alkenes increase as the number of carbon atoms increases.
Increases as molecular mass and size increases – number of electrons increases,
increases VDW forces.
For isomeric alkenes the greater the degree of branching, the lower the boiling
point.
2. Solubility
Being non-polar alkenes are insoluble in water but soluble in organic solvents.
Alkenes are soluble in non-polar solvents because their intermolecular forces are weak
and are of a similar nature and magnitude to the intermolecular forces between the
solvent molecules.
[1]
, Organic Chemistry |Alkenes, Benzene, Alkanes |Chemistry
Alkenes do not dissolve in water because water is a polar solvent with strong
intermolecular forces.
The forces between the water and alkene molecules will be weak dipole induced dipole
forces.
Reactivity
Why alkenes are more reactive than alkanes given that double bonds are stronger than single
bonds?
Only the pi-bond is broken during a reaction and more energy is released when bonds are
formed.
How is a pi-bond formed?
By sideways overlapping of two p-orbitals. It has two regions, one above and one below the
plane of the molecule.
Preparation of Alkenes:
1. From Alcohols by elimination
Reaction Reagent: Conc. Sulfuric acid or conc. Phosphoric acid
Conditions: Reflux.
[2]
, Organic Chemistry |Alkenes, Benzene, Alkanes |Chemistry
Mechanism Dehydration (elimination)
Protonation of the alcohol Using lone pair on oxygen (alcohol acts as a Lewis Base)
Loss of a water molecule to generate a Carbonium ion
Loss of a proton (H+) to give the alkene.
2. From Haloalkanes – Elimination
Mechanism Elimination
[3]
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 or Stuvia-credit 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 Alevelnotez. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $4.64. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
60904 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now