alkenes Flashcards
are alkenes saturated, or unsaturated
unsaturated, can be monounsaturated or polyunsaturated
why is there no rotation around the double c=c bond
pi orbitals of each carbon atom overlap to lock carbons in place
what happens when bromine water is added to an alkene
decolourises solution from brown to colourless
what type of intermolecular forces exist in an alkene
only Van der Waals, as there is no polar bonds
what are the three types of isomers an alkene can display
-geometric, or E/Z (cis/trans) isomerism
-position isomers (c=c double bond on different carbon atom)
-chain isomers (branched alkene)
What determines the major and minor product of addition reactions of unsymmetrical alkenes
-Markovnikov’s rule
-major product comes from the most stable carbocation intermediate and other carbocation forms the minor product
what determines how stable a carbocation is and what is this effect called
positive inductive effect
-alkyl groups push electron clouds closer to carbocation making it more reactive
-so more alkyl groups make the carbocation more stable
-tertiary carbocation most stable, primary carbocation weakest
what are the conditions needed and product for electrophilic addition of water and acid with alkenes
-acid catalyst, such as sulfuric acid
-forms an alcohol
what is an addition polymer
-monomers added together without the loss of any atoms or molecules
are addition polymers reactive
no, they are unreactive
give some uses of PVC (poly(chloroethene)) and how its properties can be modified using a plasticiser
uses such as vinyls, drainpipes or aprons
-PVC with a plasticiser becomes flexible and can be used for aprons
what is a plasticiser and give two examples
-esters and phthalates
-small molecules that get in between polymer chains to force them apart and allow them to slide over one another
why are polyalkenes unreactive
non polar bonds not attacked by enzymes
