Chapter 13- Alkenes Flashcards
What is the general formula for an Alkene?
CnH2n
What 2 bonds form a C=C bond?
sigma bonds and pi bonds
What does the pi bond do?
Restricts rotation around the C=C bond
What is the bond angle around the C=C bond?
120
Are alkenes saturated or unsaturated?
unsaturated
What 2 conditions are needed for E/Z isomerism?
A C=C double bond
Different groups attached to each carbon atom of the double bond
What is the difference between E/Z isomerism and cis/trans isomerism?
In cis/trans isomerism, one of the attached groups on each carbon atom of the double bond must be the same.
In 2 bromo-1chloropropene, using the Cahn- Ingold- Prelog system, which group has the higher priority?
Chlorine on the Carbon 1 and Brmeine of Carbon 2
What is formed when an alkene is hydrogenised?
An alkane
Write the chemical equation for C6H10 being hydrogenised.
C6H10+2H2 ->. C6H14
Write the chemical equation for C4H4 reacting with Fluorine
C4H4+ 3F2 –> C4H4F6
What 2 possible chemicals can you make when reacting but-2-ene with Hydrochloric acid.
2chloropropane
3choropropane
What 2 possible chemicals can you make when reacting but-2-ene with Water.
propan-2-ol
propan-3-ol
Define an electrophile
An electron pair acceptor
What does a curly arrow with a double head mean when drawing the mechanism of electrophilic addition?
The movement of a pair of electrons
Why does electrophilic addition work with Bromine as well as HBr?
Double bond is electron dense and so when bromine molecule comes near, the bromine atom nearest the double bond becomes positively charged
Which product is the major product when propene and Hydrogen bromide react?
2- bromopropane
Why does Markownikoff’s rule work?
The more groups attatched to the carbocation, the more stable the ion is, as the charge is more spread out. Addition of a hydrogen halide to an unsymmetrical alkene forms the major product via the most stable carbocation.
Name the monomer that forms poly(chloroethane)
chloroethene (vinyl chloride)
Give a use for poly(tetrafluoroethene)
Non- stick pans, cable insulation
Why is using waste polymers as fuel a good idea?
As they are derived from petroleum or natural gas, they have a high stored energy value
What are most biodegradable plastics made from?
Cellulose or Starch
