soaps, detergents and emulsions Flashcards
how are soaps formed
from the alkaline hydrolysis of fats and oils
how are the ester links in fats and oils broken
when they are heated with sodium or potassium hydroxide
what does hydrolysis of fats and oils produce
3 fatty acids and 1 glycerol
structure of soaps
hydrophilic head, hydrophobic tail
micelle formation
- hydrophobic tail dissolves in grease
- hydrophilic head remains in water
- agitation forms a micelle to form
- micelle is negatively charged and repels other structures, keeping grease suspended in water
what do detergents do
they work in same way as soap but are preferred in areas of hard water
what is hard water
water that contains high conc of dissolved metal ions
why are detergents used in hard water
they dont form soap scum
structure of detergents
same as soaps
what do emulsions contain
small droplets of one liquid dispersed in another, eg oil droplets mixed with water
what do emulsions do
allow stable emulsions to form
stop oil and water from separating out
how are emulsifiers for food made
by reacting edible oils with glycerol which have 1 or 2 fatty acids bonded to them
why are emulsifiers added to food
to stop oil and water in food from separating out and the food spoiling quickly
what forms the hydrophillic head and the hydrophobic tails in emulsifiers
OH groups and the glycerol forms the head and the carbon chain forms the tail
