(YELLOW) ISOMERISM Flashcards
(YELLOW) ISOMERISM
what is the definition of an structural isomer
Structural isomers are compounds that have the same molecular formula but different structural formula (i.e. different bonds present)
what are the three types of structural isomers and what do they do
Type 1. Chain structural isomers. : same molecular formula but diffrent structure
Type 2 Positional structural isomers. : basically functional group in a diffrent place
Type 3. Functional group structural isomers : same molecular formula bust diffrent functional group . e.g carboxilic group / ketone
what is the definition of a steroisoerism
Stereoisomerism is shown in molecules that have the same molecular formula and same bonds present, but different three dimensional orientations of their atoms in space.
what is geometrical isomerism
when you have an alkene the two carbons with the double bond have to have each two diffrent groups on them , thererfor causing z/e isomers / cis / trans isomers
must have C=C bond
can cyclic compounds show geometric isomerism
yes as the ring structure can cause restriction
What is a superimposable mirror image of each other?
it means that its mirror image cannot be destinguished
what is a chiral carbon
One way to identify an optical isomer is to find a carbon with 4 different groups attached to it. We call this carbon a chiral carbon or chiral centre. If the molecule has a chiral centre is will be asymmetric and therefore have optical isomers.
what is the definition of an optical isomer
Optical isomers (enantiomers) are molecules which are isomers which are non-superimposable mirror images of each other.
what featur of optical isomers does it show with light
Optical isomers ROTATE the plane of plane polarised light. Each isomer will rotate the light by the same amount but in the opposite direction.
waht is a racemic misture
A Racemic mixture is a solution which contains equal numbers of moles (concentrations) of both optically active isomers/enantiomers of a compound.
Would you expect a racemic mixture to be optically active/rotate plane polarised light?
Explain your answer.
NO
A racemic mixture contains two optical isomers / enantiomers in equimolar quantities.
One isomer rotates the plane of plane polarised light in one direction, the other isomer rotates it in an equal and opposite direction so the rotations cancel out resulting in no overall rotation of plane polarised light
what are optical isomers called
enantiomers
true or false :
Racemates contain 2 enantiomers in equal numbers
true
true or false :
The synthesis of a single optical isomer, rather than racemates, is less expensive
false
true or false :
Chiral molecules produced naturally by enzymes are usually a racemic mixture
false
