Stereoisomerism Flashcards
What are isomers?
Molecules which have the same molecular formula but differ in the way their atoms are arranged
What are structural isomers
When atoms are bonded together in a different order in each isomer
What are stereoisomers?
When the order of atoms is the same but the arrangement of the atoms in space is different
What are the two types of stereoisomerism?
Geometric and optical
Why can alkenes exhibit geometric isomerism?
Because there is no rotation around the C=C bond
What does trans and sis mean?
Cis means same side, trans means opposite side
What must an organic compound contain to form geometric isomers?
The molecule must have two different groups attached to each of the carbon atoms of the double bond
Where else can geometric isomerism occur?
Saturated rings where rotation about the C-C bond is restricted.
What is another word for an optical isomer?
An enantiomer
What is an enantiomer?
When each isomer is the mirror image of the other and is non-superimposable.
What type of molecule will have an optical isomer?
If a molecule contains a tetrahedral carbon atom with four different groups attached to it . Described as Chiral
What is the one difference between optical isomers?
Their effect on plane-polarised light
How is plane polarised light made?
By passing a beam of light through a polariser that cut out all the vibrating waves except those in one plane.
What is the effect of an optical isomer on plane polarised light?
The plane polarised light is rotated through a certain angle
Provided the concentration of the first solution is equal to the concentration of the solution containing the second isomer, what effect will the enantiomer have on plane polarised light?
The pane polarised light will be rotated through the same angle in the opposite direction.
