3.3.7-8 Optical Isomerism - Aldehydes & Ketones

Question 1

What is the definition of structural isomerism?

Answer 1

molecules with the same molecular formula but different structural formulae

Question 2

What is the definition of stereoisomerism?

Answer 2

molecules with the same structural formula but different arrangement of atoms in space

Question 3

Optical isomerism is a form of structural or stereo isomerism?

Answer 3

stereoisomerism

Question 4

What are optical isomers?

Answer 4

non-superimposable mirror images

Question 5

What is a chiral carbon?

Answer 5

A carbon atom bonded to four different groups

Question 6

What do chiral molecules do to plane-polarised light?

Answer 6

rotate it

Question 7

What is a racemic mixture?

Answer 7

A mixture which contains equal quantities of enantiomers?

Question 8

What are enantiomers?

Answer 8

non-superimposable mirror images

Question 9

What is meant by a sample which is enantiomerically pure?

Answer 9

A sample which contains only one optical isomer

Question 10

What is another name for chiral centre?

Answer 10

stereogenic centre

Question 11

Aldehydes and ketones are compounds which both contain which type of bond?

Answer 11

carbonyl bond

Question 12

An aldehyde is a compound where the carbonyl bond is located where on the carbon chain?

Answer 12

at the end

Question 13

A ketone is a compound where the carbonyl bond is located where on the carbon chain?

Answer 13

in the middle

Question 14

What is observed when Tollen’s reagent is mixed with an aldehyde?

Answer 14

silver mirror forms

Question 15

What is observed when Tollen’s reagent is mixed with a ketone?

Answer 15

No visible change

Question 16

What is observed when Fehling’s reagent is mixed with an aldehyde?

Answer 16

brick-red precipitate forms

Question 17

What is observed when Fehling’s reagent is mixed with a ketone?

Answer 17

No visible change

Question 18

What type of product is formed when an aldehyde is reduced?

Answer 18

primary alcohol

Question 19

What type of product is formed when a ketone is reduced?

Answer 19

secondary alcohol

Question 20

Name the mechanism for the reduction of an aldehyde or ketone?

Answer 20

nucleophilic addition

Question 21

What reagent is used to reduce an aldehyde or ketone?

Answer 21

NaBH4

Question 22

What condition is needed in the reduction of an aldehyde or ketone

Answer 22

acidic solvent

Question 23

Name the product formed when butanone is reduced with NaBH4

Answer 23

butan-2-ol

Question 24

Name the product formed when pentanal is reduced with NaBH4

Answer 24

pentan-1-ol

Question 25

What type of product is formed when an aldehyde or ketone is reacted with KCN?

Answer 25

Hydroxy nitrile

Question 26

Name the product formed when butanal is reacted with KCN

Answer 26

2-hydroxypentanenitrile

Question 27

What is an asymmetrical carbon?

Answer 27

A carbon with 4 different groups attached (a chiral carbon)