3.3.1 Organic definitions

carbocation

positive ion with the positive charge on a C atom

electrophile

lone pair acceptor

homologous series

group of compounds that contain same general formula and similar chemical properties. gradual change in physical properties

nucleophile

lone pair donor

saturated

molecule containing no double bonds

stereoisomers

molecules with the same molecular and structural formulae but different spatial arrangement of atoms

geometric isomers

molecules that have different arrangement of groups around the C=C double bond. eg E and Z

optical isomers

molecules which are non-superimposable mirror images

structural isomers

molecules with the same molecular formula but different structural formula

unsaturated

molecule containing double bonds

Chiral centre carbon

central carbon atom with four different groups bonded to it. no line of symmetry

enantiomers

a pair of chiral molecules that are non-superimposable mirror images of each other.

racemic mixture

pair of enantiomers in an equal 1:1 ratio. optically inactive as the opposite rotations of plane polarised light cancel out

How to distinguish between optical isomers

use plane polarised light. the enantiomers will rotate the light in different directions

E isomer

opposite

Z isomer

together - zame zide

CIP rules state that

priority is given to the group with the highest atomic number on each side

why do geometric E/Z isomers exist

there is limited rotation around the C=C double bond

fraction

mixture of compounds with similar boiling points

carbon neutral

no net emissions of CO2 to the atmosphere