carboxylic acids, acyl chlorides, esters

Question 1

why are longer carboxylic acids less soluble in water?

Answer 1

The solubility of the bigger acids decreases very rapidly with size. This is because the longer hydrocarbon “tails” of the molecules get between water molecules and break hydrogen bonds. In this case, these broken hydrogen bonds are only replaced by much weaker van der Waals dispersion forces.

Question 2

carboxylic acids + reactive metals in redox reaction….

Answer 2

• salt

- hydrogen gas.

Question 3

carboxylic acids w/ carbonates

Answer 3

• salt + water + co2

Question 4

carboxylic acids + bases ?

Answer 4

• neutralisation

- salt + water

Question 5

what is the functional group of acyl chlorides

Answer 5

-OCl

Question 6

what is general formula of acyl chlorides?

Answer 6

HnH2-1OCl

Question 7

reagent + conditions + product c.box acid -> acyl chloride

Answer 7

• SOCl2

products are acyl chloride + SO2 + HCl

Question 8

what are the 4 reactants that react w/ acyl chlorides?

Answer 8

• water
• alcohol
• ammonia
• amines

Question 9

describe reaction of acyl chloride w/ water?

Answer 9

• vigouros reaction
• c.box formed
• HCl formed

Question 10

describe reaction of acyl chloride w/ alcohol?

Answer 10

• vigorous reaction
• ester formed
• HCl formed

Question 11

describe reaction of acyl chloride w/ ammonia ?

Answer 11

• primary amide
• violent reaction
• HCl formed

Question 12

describe reaction of acyl chloride w/ amines?

Answer 12

• violent reaction
• prod secondary amide
• HCl formed

Question 13

what type of reactions do acyl chloride go through?

Answer 13

• nucleophilic addition elimination.
• Cl is substiuted by O2,Nitrogen groups.
  HCL fumes given off.

Question 14

ester formation by carboxylic acid

Answer 14

• heat alcohol with carboxylic acid
• presence of H2SO4 or acid catalyst.
• REVERSIBLE

Question 15

is esterification by carboxylic acid + alcohol reversible or not?

Answer 15

yes

Question 16

how do u separate larger esters formed by esterification of c.box + alcohol.

Answer 16

• fractional distillation

- reflux

Question 17

what is an acid anhydride?

Answer 17

• carboxylic acid derivative made up of 2 carboxylic acids

Question 18

how do u form ester w/ acid anhydride?

Answer 18

• acid anhydride
• no catalyst needed
• no reflux.
• separate by fractional distillation.

Question 19

products of acid anhydride + alcohol.

Answer 19

alcohol + carboxylic acid.

Question 20

how do u form an ester from acyl chloride + alcohols?

what is the product?

Answer 20

• acyl chloride

- H-Cl

Question 21

acid hydrolysis of esters products?

Answer 21

• ethanoic acid

- ethanol

Question 22

which type of hydrolysis is reversible?

Answer 22

• acid hydrolysis

Question 23

what conditions are needed for acid hydrolysis of esters?

Answer 23

• dilute acid (H+)

- reflux

Question 24

what conditions are needed for base hydrolysis of esters?

Answer 24

• dilute alkali
• NaOH
• reflux.

Question 25

what is formed in base hydrolysis ?

Answer 25

• sodium ethanoate

- ethanol .