ESTER, FAT & OILS

Question 1

How are esters formed?

Answer 1

condensation reaction between an alcohol and carboxylic acid - known as esterification

Question 2

Esters in water

Answer 2

Have characteristic smells and are insoluble in water

Question 3

Ester function group

Answer 3

O=C- O with R on C and single bonded O (-COO)

Question 4

Main use of esthers

Answer 4

Flavourings and perfumes can also be used in chemicals industry as solvents

Question 5

Make an esther structure

Answer 5

Hydrogen atom must be removed from hydroxyl group (-OH) of alcohol

OH from carbocyclic acid removed

Question 6

Product of esther formation

Answer 6

Water

Question 7

Naming ester

Answer 7

C=O comes from acid

change alcohol end to -yl

change acid end to -oate

alcohol name at front and acid at end

Question 8

Fat

Answer 8

do not have same degree of distortion and pack closer together for increased mp

Question 8

Hydrolysis of esters

Answer 8

break up ester by heating with ALKALI such as sodium hydroxide

water molecule added

Question 8

OIls

Answer 8

liquid at room temp

more CC double bonds than fats (solid at room temp)

lower mp due to higher degree of unsaturated

double bonds distorts long fatty acid chains and molecules shapes - cannot pack close together

Question 9

LDF fat and acids

Answer 9

poorer packing in oils so weaker

Question 10

how is glycerol obtained

Answer 10

hydrolysis - hydrolysed by NaOH

Question 11

reaction for hardening oils

Answer 11

addition - hydrogenation

Question 12

test for level of unsaturation

Answer 12

Br - decolourises with double bonds (unsaturation)