Karan Soaps and Detergents

8/22/2019 Karan Soaps and Detergents

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CONTENTSSOAP

Introduction

Saponification

Soap molecule(Micelles)

Cleansing action ofsoaps

Advantages anddisadvantages

DETERGENT

Introduction

Cleansing action ofdetergents

DIFFERENCESBETWEEN SOAPSAND DETERGENTS


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SOAPS

Soaps are the sodium and potassiumsalts of the long chain carboxylicacid.A soap molecule consists of a

long hydrocarbon chain (composedof carbons and hydrogens) with acarboxylic acid on one end which isionic bonded to metal ion usually asodium or potassium.

A soap has a large non-ionic

hydrocarbon group and an ionicrou COO-Na+.


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EXAMPLES OF SOAPS

Sodium stearate (Chemical formula:C17H35COO-Na+)

Sodium palmitate (Chemical formula:C15H31COO-Na+)

Sodium oleate (Chemical formula:C17H33COO-Na+)


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SAPONIFICATIONThe process of making soap bythe hydrolysis of fats and oils with

alkalies is called saponification.

Soap is made by heating animalfats or vegetable oil withconcentrated sodium hydroxide(NAOH).

Fat or Oil + NaOH Soap +Glycerol

MICELLES SOAP


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MICELLES SOAPMOLECULES

A soap molecule has twoends with differentproperties-

1. A long hydrocarbon partwhich is hydrophobic (i.e.it dissolves in

hydrocarbon).2. A short ionic part

containing COO-Na+

which is hydrophilic (i.e.it dissolves in water).

micelle


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MECHANISM OF SOAPSWhen a dirty cloth is put is put

in water containing soap thanthe hydrocarbon ends of thesoap molecule in the micelleattach to the oil or grease

particles present on the surfaceof dirty cloth. In this way thesoap micelles entraps the oilyparticles by using thehydrocarbon ends. The ionic

ends of the soap moleculesremain attached to the waterwhen the dirty cloth is agitatedin soap solution. The oily

particles presents on its surfacegets dispersed in the water due


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ADVANTAGES & DISADVANTAGES

ADVANTAGES

Soaps areeco-friendlyand bio

degradable

DISADVANTAG

ESSoaps are notsuitable in the

hard water.They haveweak cleansing

properties than


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DETERGENTSDetergents are the sodium salts oflong chain benzene sulphuricacids.

Detergents are primarilysurfactants, which could beproduced easily frompetrochemicals. Surfactants lowerthe surface tension of water,essentially making it 'wetter' sothat it is less likely to stick to itself

and more likely to interact with oil


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EXAMPLES OF DETERGENTSTwo basic examples of well-known detergents of the

sulphonate group or the sulphate group are:


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DETERGENTS

Synthetic detergents have the same type of

molecular structure as soaps i.e. a tadpole likemolecule having two parts at each end i.e., onelarge non-polar hydrocarbon group that is waterrepelling (hydrophobic) and one short ionicgroup usually containing the or group that iswater attracting (hydrophilic). Thus thecleansing action is exactly similar to that ofsoaps whereby the formation of micellesfollowed by emulsification occurs. However,synthetic detergents can lather well even inhard water. This is because they are solublesodium or potassium salts of sulphonic acid oralkyl hydrogen sulphate and similarly formsoluble calcium or magnesium salts on reactingwith the calcium ions or magnesium ionspresent in water. This is a major advantage of


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ADVANTAGES OF DETERGENTS

Since detergents are the salts of strongacids they do not decompose in acidicmedium. Thus detergents can effectivelyclean fabric even if the water is acidic.

Synthetic detergents are more soluble inwater than soaps.

They have a stronger cleansing action

than soaps.

As detergents are derived frompetroleum they save on natural vegetable

oils, which are important as essential


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DISADVANTAGES OF DETERGENTS

Many detergents are resistant to the

action of biological agents and thus arenot biodegradable. Their elimination frommunicipal wastewaters by the usualtreatments is a problem.

They have a tendency to produce stablefoams in rivers that extend over severalhundred meters of the river water. This is

due to the effects of surfactants used intheir preparation. Thus they pose a dangerto aquatic life.

They tend to inhibit oxidation of organic

substances present in wastewatersbecause the form a sort of envelo e

DETERGENTS


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DETERGENTS

SOAPS

They are metalsalts of long chainhigher fatty acids.

These are

prepared fromvegetable oils andanimal fats.They cannot be

used effectively inhard water as theyproduce scum i.e.,insoluble

precipitates ofCa2+, Mg2+,

DETERGENTS

These are sodium saltsof long chainhydrocarbons like alkylsulphates or alkylbenzene sulphonates.

They are prepared fromhydrocarbons ofpetroleum or coal.These do not produce

insoluble precipitates inhard water. They areeffective in soft, hard orsalt water.


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