how soap acts as an emulsifying agent and its property that qualifies it as an emulsifying agent?

Question

Soap is a common emulsifying agent.

Answer 1

The most common type of soap molecule is sodium stearate, CH3(CH2)16COO- Na+. Stearic acid is common in animal and vegetable fats, so people have made soap since ancient times by boiling fats with soda and potash.

The long chain of CH2's acts like an organic solvent or cleaning fluid, because it "looks" like grease or oil. The -COO-Na+ head has an affinity for water. So overall, soap gets greases and oils into a water emulsion, which is something like a solution.

Soap forms micelles in water. A micelle is a ball with the -CH2- tails buried inside, and the surface facing the water covered with -COO-Na+ groups. Greasy and oily molecules incompatible with water are "dissolved" inside among the hydrocarbon tails.

One objection to the micelle idea is that there isn't enough room inside the ball for all those tails if the surface has to be covered by -COO-Na+. But micelles do exist, and if they don't look like that, they must look like something close.

Answer 2

soap contains the salts of fatty acids. fatty acids have extremely long hydrocarbon chains (10-20carbons) with a carboxylic acid group at the end. the salt is of course the ionised version, this includes sodium or potassium salts so the surfactant molecule actually looks like CH3(CH2)10COONa since this molecule has a charged group (COO-) it can form ion-dipole bonds with water (polar bonds, to be less specific). the long alkyl chain also means that this molecule can form bonds with nonpolar molecules such as oils. therefore 1 soap molecule can bond to both water and oil, so it is termed a surfactant, or an emulsifying agent that stabilises two otherwise immiscible liquids (oil and water).

Answer 3

remember soaps are made from animal fats or plant oils and are boiled with conc.NaOH solution to form sodium sterate and glycerol.At one end of the molecule group of atoms which disssolve in water.at the otherr end is a chain of atoms which donot dissolve in wtaer but dod issolve in oily compounds.when soap is added the waterthe water soluble end of the molecule dissolves in the water destroying the surface tension helpin the water to spread out n penetrate the cloth .this loosens the dirt particles when the dirty garment is agitated similar;y the oil soluble ends dissolve in any grea or oil and breakdown so tht it is removed.
HOPE THT HELPS

Answer 4

Look thru your biology text and look at the section on membranes. You will quickly find this by looking up words like "hydrophobic" and/or "hydrophilic" in what we call an "index".
From there, you're good to go.

Now go do your homework.