Consumer and Industrial Chem (Fats and Oils) Flashcards
(60 cards)
What is an example of saturated fats
- tristearin
- tripalmitin
State 2 differences between saturated fats and unsaturated fats
Saturated : Unsaturated
Carbon-carbon single b : Carbon-carbon double b
high melting point : Low melting point
made of glycerol & saturated fatty acid : made of glycerol & unsaturated fatty acid
What type of fat is oleic acid?
monounsaturated fat
what process can convert unsaturated fats to saturated fats?
- catalytic hydrogenation
- hydrogen gas is passed into hot liquid oil with nickel as catalyst
what process can convert unsaturated fats to saturated fats?
- catalytic hydrogenation
- hydrogen gas is passed into hot liquid oil with nickel as catalyst
Why does liquid unsaturated fats change to solid after hydrogenation?
- More and more double bond is hydrogenated, the relative molecular mass and molecular size increases.
- Intermolecular forces become stronger
- more heat energy is required to overcome the stronger intermolecular forces
- boiling point of oil increases, liquid changes to solid
How can soap be produced?
Through saponification
- hydrolysis of fats / oils by alkalis(Naoh or Koh) into fatty acid salt and glycerol
- NaCl is added to reduce solubility of soap in water
- to precipitate the soap obtained
Is ROSO3Na sodium alkyl sulphate or sodium alkylbenzene sulphonate?
sodium alkyl sulphate
Which part of the soap, when ionised in water, is hydrophilic?
- carboxylate end of the soap anion
- attracted and soluble in water
soap dissolves and ionises in water to produce ____?
soap anion and sodium / potassium ion
What does hydrophobic mean?
- soluble in oil / grease
Why can’t detergent with branched hydrocarbon chain be biodegradable?
- The branched chain molecules blocks the enzyme action of microorganisms
- decomposition of detergent molecule is prevented.
Why won’t small droplets of grease in water reattach to the cloth after detergent / soap is added?
- repulsion of negative charges of the hydropilic part of the soap/detergent anion on the surface of grease
what is the function of optical whitening in detergent? give and example of optical whitening
make the clothes whiter, fluorescent dyes
example of water softener in detergent
sodium tripolyphosphate (enhance effectiveness of detergent by softening the water/combining with mg ions n ca ions)
example of anti-suspension agent
sodium carboxylmethylcellulose (prevent dirt from reattaching onto clothes)
example of whitening agent
sodium hypoclorite n sodium perborate (change dirt to colourless substance)
diff between whitening agent n optical whitener
whitening agent: change dirt to colourless substance
optical whitener: make clothes brighter n whiter
what is the use of preservative, sodium nitrite, in food?
used in sausages, burgers, luncheon meat
to preserve the red colour of meat
benzoic acid as preservatives r commonly used in?
oyster sauce, tomato sauce, chilli sauce, juices
function of stabiliser and give an eg
to provide uniform n smooth texture
- pectin to thicken jams
- agar from seaweed to make jellies
to prepare alkyl benzene sulphonate salt, ___ Is added into alkylbenzene to form ____ during sulphation
concentrated sulphuric acid
alkylbenzene sulphonic acid
give 2 examples of flavourings
- monosodium glutamate (msg) in instant noodles
- aspartame, sorbitol, stevia as sweeteners
- esters like propyl ethanoate for pear flavour, ethyl ethanoate for pineapple flavour
During neutralisation in preperation of detergent,
alkylbenzene sulphonic acid + sodium hydroxide –> ____ +____
alkylbenzene sulphonate salt + water
