Alkenes Flashcards
(16 cards)
What are alkenes?
Unsaturated hydrocarbons that contain at least one C=C bond made up of a pi bond and a sigma bond
How is a pi bond formed?
Electrons in the adjacent p orbitals overlap above and below the carbon atoms. They can only be made after a sigma bond is formed.
What bond restricts the rotation of carbon atoms?
Pi bond
What is the angle and shape of a double bond?
Trigonal Planar
120 degrees
Are alkenes more or less reactive than alkanes? Why?
More reactive due to high electron density of double bond and the fact the pi-bond is slightly easier to break
What intermolecular forces of attraction do they have?
Only London forces due to non-polar bonds
Are alkenes soluble in water? Why?
No due to non polar bonds
What are the types of isomers that can be formed using alkenes?
E/Z isomers- due to the restricted rotation
Cis/Trans isomers- if two of the same substitutents are attached to each carbon
What is an electrophile?
Species that are electron pair acceptors
What is the most stable type of carbocation? Why?
Tertiary Carbocation
The carbocation bonded to the most other carbon atoms
What is the reaction called when a halogen is added to an alkene?
Halogenation
Major products are formed from which kinds of carbocations?
The most stable carbocation
What are the products of the hydration reaction?
An alcohol
How does a molecule with a non-polar bond react as if it is an electrophile?
C=C double bond with a high electron density induces a temporary dipole in the halogen molecule
Delta plus atom attracted to double bond
What is an oxidising agent?
Electron acceptor/gains electrons (gets reduced)
What conditions are needed for the electrophilic addition of a hydrogen halide to an alkene?
Hydrogen Halide gases must be at room temperature
