exp 4: saponification: soap making Flashcards
it is the process by which soaps, carboxylate salts with very long hydrocarbon chain, are made from hydrolysis of a fat or an oil
saponification
they are made from hydrolysis of a fat or an oil
carboxylate salts:
water-loving
helps soap dissolve in water
very long hydrocarbon chain:
oil-loving
helps wash away dirt when you use soap
this reaction has been known and adopted as a method for soap making for centuries
saponification
how was soap were made traditionally
from animal fat (like lard) and lye (NaOH)
saponification figure
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what are fats and oils made of
triesters of glycerol (a type of alcohol)
3 fatty acids (long hydrophobic tails - this is why fats and oils cannot mix with H2O)
insoluble in water
long hydrophobic tails, fats, oils and fatty acids
esters can be hydrolyzed to what components
alcohol
carboxylic components
presence of acids and bases
what happens if a base is used for hydrolysis
fatty acids produced are deprotonated and are present as the corresponding carboxylate salts
base breaks down fats (hydrolysis) >
splits fat molecule >
remove proton H+ from FA (deprotonated)
carboxylate salt
- lose H+
- negative charged = form salt
- able to mix w H2O better than regular FA
they are more soluble in water than the corresponding uncharged fatty acids
carboxylate salts that are charged
carboxylate salts contains
long nonpolar tail
compatible with nonpolar greases and oils
how are soap abble to emulsify fats and ois
by forming micelles around the oil droplets
what happens in the presence of enough soap kolecules surrounding oil droplets
oil droplets become dispersed in water where then can be easily washed away
how can one help wash greasy dishes more easily
using lots of soap
hot water (can melt solid fats)
agitation (can break up fats and oils into smaller droplets)
how do we make soap in this experiment
using coconut oil by heating it w NaOH
udergo precipitation through a concentrated salt soln
what should the final product be after subjecting the samples to vacuum filtration
solid soap sample
reagents used
20% NaOH - base, reacts with fatty acids and coconut oil
Ethanol - helps dissolve the fats and improve the mixture of reactants
30% NaCl - precipitate the soap after reaction, separate soap from the mixture
Cold distilled water - wash away impurities while keeping the soap solid
how many grams/ mL of
coconut oil -
ethanol -
NaOH -
NaCl -
coconut oil - 5g
ethanol - 15ml
NaOH - 15ml
NaCl - 50ml
how long do u have to heat the mixture
30min with constant stirring using a magnetic stirrer
until the soln no longer has 2 separate layers
where do u dispose the used filter paper
solid waste disposal
soap molecules help mix oil and water by surrounding oil droplets and allowing them to stay suspended in water
emulsification
