Organic chemistry - 4

Question 1

when oxidising an alcohol, what is the catalyst used?

Answer 1

acidified potassium dichromate (H+/Cr2O7^2-)

Question 2

how can a carboxylic acid be made from an ester?

Answer 2

ester -(water)-> alcohol+ carboxylic acid

Question 3

amide -(water)-> ?

Answer 3

amide -(water)-> carboxylic acid + salt

Question 4

what three molecules can be broken down by hydrolysis to produce a carboxylic acid?

Answer 4

• ester
• amide
• nitrile

Question 5

three substances that form salts when reacted with carboxylic acids

Answer 5

• some metals
• carbohydrates
• alkalis

Question 6

amine + carboxylic acid -(HEAT)-> ? + ?

Answer 6

amine + carboxylic acid -(HEAT)-> amide + water

Question 7

what is an amine?

Answer 7

organic derivatives of ammonia where one or more hydrogen atoms in ammonia is replaced by alkyl group

Question 8

what are the three classification of amines?

Answer 8

primary, secondary, tertiary

Question 9

how are amines classified?

Answer 9

according to the number of alkyl groups attached to nitrogen

Question 10

what do primary/secondary amines contain that allow them to have a higher b.p compared to their isomeric tertiary amines?

Answer 10

polar N-H bond - hydrogen bonds between molecules

Question 11

why are amines known as weak bases?

Answer 11

lone pair of electrons on nitrogen atom accepts a proton from water molecule

Question 12

what can amines react with to form salts?

Answer 12

mineral acids and carboxylic acids

Question 13

what is the simplest aromatic hydrocarbon?

Answer 13

benzen (C6H6)

Question 14

when benzene is added to bromine does the bromine decolourise?

Answer 14

no - benzene is more stable than typical unsaturated hydrocarbon

Question 15

what type of hybridisation occurs in each carbon atom of benzene?

Answer 15

sp2 hybridisation

Question 16

what do the three half-filled sp2 hybrid orbitals form in benzene?

Answer 16

σ bonds

Question 17

benzene: on each carbon atom there is an electron occupying a p orbital - what occurs due to this?

Answer 17

side-on overlap occurs and a π electron cloud is formed

Question 18

what bonds are there in a benzene molecule?

Answer 18

• 12σ bonds

- π electron cloud that contains delocalised electrons

Question 19

why is benzene stable?

Answer 19

due to delocalised electrons

Question 20

what type of reaction do benzene molecules undergo?

Answer 20

electrophilic substitution reactions

Question 21

what are the 4 electrophilic substitution reactions that benzene can undergo?

Answer 21

• alkylation
• chlorination
• nitration
• sulfonation

Question 22

what is the reagent used in alkylation?

Answer 22

CH3Cl/AlCl3

Question 23

what is the reagent used in chlorination?

Answer 23

Cl2/FeCl2

Question 24

what is the reagent used in nitration?

Answer 24

c.HNO3 or c.H2SO4 acids

Question 25

what is the reagent used in sulfonation?

Answer 25

c. H2SO4

Question 26

what type of drug mimics the body naturally active molecule?

Answer 26

agonist

Question 27

how does an agonist work?

Answer 27

binds to receptor site and triggers same response as natural molecule

Question 28

what type of drug prevents the naturally active molecule from binding?

Answer 28

antagonist

Question 29

how does an antagonist work?

Answer 29

• binds more strongly to receptor site

- blocks site and natural response not triggered