2.3 Stereochemistry

Question 1

isomer

Answer 1

molecules that have the same molecular formula but different structural formulae

Question 2

molecules that have the same molecular formula but different structural formulae

Answer 2

isomer

Question 3

structural isomer

Answer 3

occurs when atoms are bonded together in a different order in each isomer

Question 4

Structural isomer

Answer 4

occurs when atoms are bonded together in a different order in each isomer

Question 5

occurs when atoms are bonded together in a different order in each isomer

Answer 5

structural isomers

Question 6

stereoisomer

Answer 6

• occur when the order of the bonding in the atoms is the same but the spatial arrangement of the atoms is different in each isomer
• two categories: geometric and optical

Question 7

• occur when the order of the bonding in the atoms is the same but the spatial arrangement of the atoms is different in each isomer
• two categories: geometric and optical

Answer 7

stereoisomer

Question 8

geometric isomer

Answer 8

• can occur when there is a restricted rotation around a C=C or a C-C in a cyclic compound
• must have two different groups attached to each carbon atom that make up the bond with restricted rotation
• the substituent groups are on the same side (cis) or different sides (trans) of the bond with restricted rotation
• have differences in physical properties, such as MP and BP
• can have differences in chemical properties

Question 9

• can occur when there is a restricted rotation around a C=C or a C-C in a cyclic compound
• must have two different groups attached to each carbon atom that make up the bond with restricted rotation
• the substituent groups are on the same side (cis) or different sides (trans) of the bond with restricted rotation
• have differences in physical properties, such as MP and BP
• can have differences in chemical properties

Answer 9

geometric isomers

Question 10

optical isomer

Answer 10

• occurs in compounds in which different groups are arranged tetrahedrally around a central C atom (chiral carbon chiral centre)
• are asymmetrical
• are non superimposable mirror images of eachother
• can be described ad enantiomers
• have identical physical properties, except for their effect on plane-polarised light
• have identical chemical properties, except when in a chiral environment such as that found in biological systems (only one optical isomer is usually present)
• rotate plane-polarised light by the sane amount but in opposite directions and so are optically active
• when mixed in equal amounts are optically inactive because the rotational effects of the plane-polarised light cancels out - this is called a racemic mixture

Question 11

• occurs in compounds in which different groups are arranged tetrahedrally around a central C atom (chiral carbon chiral centre)
• are asymmetrical
• are non superimposable mirror images of eachother
• can be described ad enantiomers
• have identical physical properties, except for their effect on plane-polarised light
• have identical chemical properties, except when in a chiral environment such as that found in biological systems (only one optical isomer is usually present)
• rotate plane-polarised light by the sane amount but in opposite directions and so are optically active
• when mixed in equal amounts are optically inactive because the rotational effects of the plane-polarised light cancels out - this is called a racemic mixture

Answer 11

optical isomers