Flashcards in a level Alkenes Deck (18)
what is the nature of the double bond?
a sigma bond surrounded by a pi bond
what is a pi bond?
the overlap of two p orbitals
what shape are alkenes and why?
3 regions of e- density around each c atom
all in the same plane
what are stereoisomers?
have the same structural formula but a different arrangement of atoms in space
what conditions are required for E/Z isomerism?
a c=c double bond
different groups attached to each c of the double bond
what is cis-trans isomerism?
where one of the groups on each carbon is hydrogen
what is the Cahn-Inglod-Prelog rule?
what distinguishes E/Z isomers
how do you determine an atoms priority?
highest atomic no.
why are alkenes relatively reactive?
the pi bond breaks easily
why does the pi bond break easily?
bond enthalpy is weaker
what addition reactions do alkenes undergo?
what conditions for hydrogenation?
423K and nickel catalyst
what conditions for halogenation?
none but adding bromine water tests for unsaturation
what conditions for the addition of hydrogen halides?
what conditions for hydration?
phosphoric acid catalyst
why does electrophilic addition occur?
the double bond is an area of high e- density
this attracts electrophiles
what is an electrophile?
a small molecule that accepts an electron pair and is added across the double bond