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Flashcards in Alkenes Deck (16):

What are stereoisomers?

Compounds with the same structural formula but a different arrangement in space


What is E/Z isomerism?

Stereoisomerism in terms of restricted rotation around a C=C double bond


What special part is needed in the name of an alkene?

En or Ene


What is the name of the main bond and the secondary bond in a double bond?

Main bond = Sigma bond
Secondary bond = Pi bond


How does a pi bond form?

The sideways overlap of two P orbitals


Which bond is weaker, sigma or pi?

Pi bond


What do the CIP rules state about E/Z isomerism?

The group with a larger atomic mass on the end of a bond is the higher priority group.


What do E and Z mean in E/Z isomerism?

E = Entgegen = Apart = Opposite sides
Z = Zusammen = Together = Same sides


What are the four addition reactions of alkenes and what are their conditions?

1. Addition of Hydrogen - Nickel catalyst
2. Halogens (i.e Cl2) - RTP
3. Hydrogen Halide (e.g. HBr)
4. Addition of Water - Phosphoric acid catalyst


What is the mechanism of addition to alkenes and how is it shown?

Electrophilic addition
1. Line from double bond to delta positive charge atom, and line from the molecule's bond to the delta negative atom
2. Line from the electron pair on the negative ion
3. Complete new product


What does electrophile mean?

Attracted to pairs of electrons


What does Markownikoff's rule state?

The non-hydrogen atom goes to the carbon with most carbons attached


How is atom economy calculated?

Mr of desired product
---------------------------------- x 100
Sum of Mr of all products


How is percentage yield calculated?

Actual amount
--------------------------- x 100
Theoretical amount


How does addition polymerisation work?

Multiple small monomers


How can we deal with polymer waste?

1. Producing photodegradable/ biodegradable polymers
2. Combustion of waste polyerms to generate energy
3. Reuse of material as a feedstock for the chemical industry