Aldehydes and Ketones

Question 1

What are Aldehydes reduced to?

Answer 1

1° Alcohols

Question 2

What are ketones reduced to?

Answer 2

2° alcohols

Question 3

what is a nucleophile?

Answer 3

Electron pair donor

Question 4

What mechanism reduces ions and ketones to alcohols?

Answer 4

nucleophilic addition

Question 5

what is the reagent for nucleophilic addition alcohols?

Answer 5

NaBH4

aqueous solution

Question 6

what is the equation for a nuclear for addition to form alcohols?

Answer 6

A/K + 2[H]> alcohol

Question 7

what is hazardous about potassium cyanide (KCN)?

Answer 7

it is an irritant and toxic when eaten

When it reacts with water, it forms HCN, which is a highly toxic gas

Question 8

when reducing aldehydes and ketones using KCN,how this be carried out to ensure safety

Answer 8

in a fume cupboard with goggles, gloves and a Lab coat

Question 9

What does potassium cyanide (KCN) reduce aldehyde and ketones to?

Answer 9

Hydroxynitries

Question 10

what is the overall equation for nucleophilic addition to form hydroxynitriles?

Answer 10

A/K + KCN + HCL > hydroxynitrile + KCL

Question 11

What is an optical isomer (enantiomer) ?

Answer 11

same chemical and physical properties

contain a chiral centre

Question 12

what is a chiral centre?

Answer 12

A single carbon atom is bonded to 4 different atoms/groups

Question 13

what are the properties of an asymmetric carbon?

Answer 13

• no centre of symmetry
• no plane of symmetry
• no axis of symmetry

Question 14

what is the one difference between enantiomers?

Answer 14

They rotate the plane of polarise light in opposite directions

Question 15

what is a racemic mixture?

Answer 15

contains equal amounts of an enantiomer and is optically inactive

Question 16

what happens if a sample is optically active?

Answer 16

enantiomers i’m not equal so a rotation of the light will be detached

Question 17

what does that mean if a sample is optically inactive?

Answer 17

enantiomers are an equal amount and they rotate the plane of authorise light in opposite directions equally

Question 18

why are some drugs optically active?

Answer 18

body may have a specific enzyme based receptor which will only accept a particular isomer

leadss to effective/effective drug isomers

Question 19

How do you overcome the problem of optical active drugs?

Answer 19

• separate the two isomers (difficult because they have the same chemical properties)
• Sell the drug as a mixture so half of it is useless
• Only make the required isomer

Question 20

what creates equal amount of enantiomers

Answer 20

the C=O bond in A/K is planar

so there is equal chance of the nucleophile attacking the delta positive carbon from above AND below the plane of the molecule

so enantiomers are formed in equal amounts