U2 P4 - soaps, detergents + emulsions

Question 1

fats + oils

Answer 1

can be used to make soaps, detergents + emulsions

Question 2

saponification

Answer 2

the process of making soap by hydrolysing edible oil using an alkaline solution
fatty acid + sodium hydroxide —> soap + water

Question 3

soaps

Answer 3

sodium salts of fatty acids

Question 4

detergents

Answer 4

compounds with a soap-like structure

non-polar tail which is oil soluble and a and a polar which is water-soluble

Question 5

difference between detergent head + soap head

Answer 5

detergent - sulphonate head

soap - carboxylate head

Question 6

structure of soaps

Answer 6

long covalent hydrocarbon tail which is soluble in non-polar compounds - hydrophobic

polar ionic charged head which is water-soluble - hydrophilic

Question 7

cleansing mechanism of soaps

Answer 7

hydrophobic tail burrows into droplet of oil/grease

hydrophilic heads are left to face the surrounding water

this results in formation of a ball-like structure

non-polar substance such as oil/grease are held inside the ball and suspended in water to be washed away

Question 8

emulsions

Answer 8

liquids which contain small droplets of another liquid, usually separates into 2 layers

Question 9

role of emulsifier

Answer 9

keeps water-soluble and oil-soluble compounds together

have a non polar and polar part

Question 10

formation of emulsifier

Answer 10

reacting edible oils with glycerol

Question 11

emulsifier structure

Answer 11

hydroxyl groups are hydrophilic
fatty acid chains are hydrophobic
fatty acid chain therefore dissolves in oil whilst the hydroxyl groups dissolves in water, forming a stable emulsion