HISTORY OF SOAP

MANUFACTURING

Soaps have been used for more than 3000 years. In ancient

times, soaps were made from plant ashes (contain potassium

carbonate) and animal fats. Plant ashes were dispersed in water,

and fat was added to the solution.

Ash + Lime boiled Caustic Potash(K2CO3) (CaO) (KOH) Caustic Potash + Animal Fats boiled Soap

Animal fats contain fatty acids which helped to get the process

started. In the end of the Middle Ages, slaked lime used to

causticise the alkali carbonate. Through this process, chemically

neutral fats could be saponified easily.

The introduction of the Leblanc process for the production of

soda ash from brine and by the work of a French chemist, Michel

Chevreul, who showed that the process of saponification is the

chemical process of splitting fat into the alkali salt of fatty acids

(that is, soap) and glycerin help in the manufacturing of soap.

SOAP AND DETERGENTS

SOAPSoap is the sodium or potassium salts formed when a fatty acid

that contain 12 to 18 carbon atoms per molecule is neutralized

by an alkali.

Fats or vegetable oils + concentrated alkalis soap +glycerol

Soap is cleansing agent made from animal fats or vegetable oils

by saponification.

Saponification is the alkaline hydrolysis of ester using alkali solutions. Some examples of soaps are shown below.

a) Sodium palmitate, C15H31COONab) Sodium oleate, C17H33COONac) Sodium stearate, C17H35COONa

The process through which soap is preparedSoap is prepared by heating fats and oils with an alkali such as sodium hydroxide, NaOH. The oil and fat malecules are hydrolysed to form glycerol and fatty acids. This process is also known as saponification as is the reverse of esterification.

The fatty acids formed react with sodium hydroxide, NaOH a

form a salt and water. This salt is the basic form of soap.

Saponication of oils or fats O ll R’—C—O—CH₂ OH—CH₂ O l ll OH ⁻ OH—CH + R’COOH + R”COOH R”’COOH R”— C—O—CH + 3H₂O l O OH—CH₂ fatty acids ll R”’—C—O—CH₂ glycerol Ester

Neutralization of fatty acids

R’COOH + R”COOH + R”’COOH + 3NaOH R’COONa + R”COONa + R”’COONa + 3H₂O

Salt or fatty acids or soap

The soap produced can be precipitated by adding sodium

chloride, NaCl to the reaction mixture. Sodium chloride, NaCl

reduces the solubility of soap in water. As a result, the

precipitation of soap occurs.

The preparation of sodium palmitate when glyceryl tripalmitates

(ester) is boiled with concentrated sodium hydroxide, NaOH

solution, saponification occurs and a mixture of sodium palmitate

(soap) and glycerol is obtained.

The structure of soap molecule

When soap is dissolved in water, it will dissociate and produce sodium ions and carboxylate ions (RCOO-). For example, sodium stearate dissolves in water to form sodium ions and stearate ions.

C17H35COONa (s) + water C17H35COO- (aq)sodium stearate stearate ions

+ Na + (aq)

The active substance in soap is the carboxylate ion, for example, stearate ion. The stearate ion consist of two parts : the ‘head’ and the ‘tail’. The ‘head’ id negatively charged and the ‘tail’ is a long hydrocarbon chain.

The ‘head’ contains the -C-O- ions which dissolves readily in water (hydrophilic) but does not dissolve in oil. Conversely, the ‘tail’ contains a long hydrocarbon chain which is insoluble in water (hydrophobic) but dissolves readily in oil.

O

Soaps made from palmitic acid are known as sodium palmitate. Figure 5.2 shows the structure of the palmitate ion in soaps. The figure 5.3 9a) shows the molecular model of palmitate ion and Figure 5.3 (b) shows the simple representation of the structure of the palmitate ion.

The molecular model of the palmitate ion.

The diagrammatic representation of the soap ion.

DETERGENT

DETERGENT

Detergent is the salt formed when an alkyl hydrogen sulphate

is neutralized by an alkali

Detergent is synthetic cleansing agent made from

hydrocarbons obtained from petroleum fractions.

Detergents can be classified into three main types, depending on the charge on the detergent ion.a) Anionic detergents where the head of the detergent

particle contains a negatively charged ion.Example: R – O – SO3

-Na+ (Sodium alkyl sulphate)

b) Cationic detergents where the head of the detergent particle contains a positively charged ion.Example: R – N (CH3)3

+BR-

c) Non ionic detergents

Example: R – O – CH2CH2OH

There are two types of anionic detergents : a) Detergent molecule with a benzene ring such as sodium

alkylbenzene sulphonate.

Where R represents a long hydrocarbon chain.

We can represent the detergent ion, alkylbenzene sulphonate ion, more simply as :

Positively charged ion

Negatively charged ion

b) Detergent molecule without a benzene ring such as sodium alkyl sulphate.We can represent the detergent ion, alkyl sulphate ion as:

R – OSO3-

The process through which detergent is prepared

i. Preparation of of sodium alkyl sulphate

i. Reaction with concentrated sulphuric acid

ii. Neutralisation with sodium hydroxide, NaOH solution

Preparation of sodium lauryl sulphate from the production

of lauryl hydrogen sulphate followed by the neutralization

of lauryl hydrogen sulphate.

An example of a long chain alcohol is didecan – 1 –ol, CH3(CH2)10CH2OH. The detergent prepared from dodecan -1 –ol is called sodium dodecyl sulphate (IUPAC name) or sodium lauryl sulphate (common name). CH3(CH2)10CH2O-SO3

-Na+ .Sodikum alkylbenzene sulphinates, were first used in 1940s. It can be prepared in three steps. The starting materials for making this detergents in a long chain alkene, RCH = CH2 , obtained from the cracking of petroleum.

Preparation of sodium alkylbenze sulphonatea) Alkylation – introduction of the sulphonic acid group

to an organic molecule

b) Sulphonation – introduction of the sulphonic acid

group , -SO3H to an organic molecule to form sulphonic acid

Alkylbenze reacts with sulphuric acid to form alkylbenze sulphonic acid

c) Neutralisation

Alkylbenzene suphonic acid reacts with sodium

hydroxide to form sodium alkylbenze sulphonate

(detergent)

The structure of detergent molecule

Detergents dissolve in water to form sodium ions, Na+ and

detergent ions.

The detergent ions consists of two parts; the head and the

tail.

The head is the sulphate group, -OSO3- or the sulphonate

group, -OSO3- , which is negatively charged and hydrophilic

(dissolves in water).

The tail is the long hydrocarbon chain, which is neutral and

insoluble in water (hydrophobic) but dissolves readily in oil or

grease.

The structure of alkyl sulphate ion in detergent

alkyl sulphate ion

Alkylbenzene sulphonate ion

The cleansing action of soap and detergent

a) When soap or detergent is added to the dirty surface

of a piece of cloth, the hydrophohic part of the soap

or detergent ions dissolves in grease. The hydrophilic

part of the soap or detergent ions dissolves in water.

b) If the water is agitated and lifted off the surface.

c) The grease is lifted off the surface and suspended in

water. The hydrophilic part of the soap or detergent

ions surround the grease.

d) The grease is dispersed into smaller drops that float

in water. Heating, rubbing, and scrubbing can help

this process.

e) When the cloth is rinsed with water, the grease

droplets will be removed.

The effectiveness of the cleansing action of soap and detergent

Additives in detergents

Property Soap Detergent

Cleaning power Less powerfull More powerfull

Ease of rinsing It is difficult to wash away all soap on clothes. The soap that remains leave and odour and spoils the fabric

Rinse out well from clothes

pH Slightly alkaline Can be controlled to suit the cleaning task

Molecular structure

Determined by the fatty acids found in the oil or fat used to produce soap

Can be modified to suit the cleaning task. For example, a detergent can be made specially for cleaning toilet bowls.

Formation of scum

Forms scum with hard water

Does not form scum with hard water

1. Modern detergents used for washing clothes usually contains a

few types of additives to :

a) Increase their cleaning power.

b) Make them attractive and saleable.

2. Only about 20% of the substances in a detergent are cle4ansing

agents (sodium alkyl sulphate or sodium alkylbenzene

sulphonate). The other substances are additives. The examples

of addictives and their functions are described as follows :

3. Builders : Sodium tripolyphosphate (Na 5P3O10)

a) Sodium tripolyphospathe is usd to soften hard water. In the

presence of sodium tripolyphosphate, Ca2+ ions and Mg2+

ions are removed.

b) Sodium tripolyphosphate increases the pH value of water.

In this way, muddy dirt can be removed.

4. Whitening / bleaching agents : sodium perborate

a) Bleaches (bleaching agents) remove coloured stains by

oxidation process. When coloured stanis are oxidized, the

colour will disappear.

b) The whitening (bleaching) agents commonly used in

detergent are sodium perborate (NaH2BO43H2O). Sodium

perborate decomposes in hot water to release oxygen (an

oxidising agent) which is responsible for the whitening

(bleaching) action.

c) Unlike chlorine, oxygen does not bleach the colour of dyes

are not damaging to fabrics. When properly used, the

perborate bleaches make fabrics whiter than chlorine

bleaches and the colourful dyes of the fabrics do not fade

when dirty stains are removed.

d) Besides sodium perborate, sodium hypochlorite, (NaCIO)

can also be used as bleaches in detergents. The IUPAC

name of sodium hypochlorite is sodium chlorate (I).

e) Sodium hypochlorite releases chlorine that bleaches with

dirty stains. However, high concentrations of chlorine can

be quite damaging to fabrics. These bleaches do not work

well on synthetic fabrics (polyster fabrics), often causing a

yellowing rather than the desire whitening. Also chlorine

causes the dyes on fabrics to fade.

5. Biological enzymes : Amylase, lipase, and protease

a) Protein stains such blood, milk, and tomato sauce cannot

be removed by the ordinary detergents because these

types of stains are insoluble in water.

b) Biological enzymes in detergents can break down fat and

protein molecules in food stains. The fatty acids, glycerol

and amino acids produced are soluble in water and are

removed during washing.

6. Brighteners

a) Figure below shows the action of brighteners. The

brighteners absorb the invisible ultra-violet and re-radiate

it as blue light.

Brightener

Cloth

b) Brighteners make fabrics appear whiter and brighter

because the blue light can hide any yellowing on the

fabrics. Blue light added to the yellow light reflected on old

fabrics make them look white.

7. Drying agents ; Sodium sulphate and sodium silicate

Anhydrous sodium sulphate and sodium silicate (Na2S2O3) are

used as drying agents to ensure that the detergent in powdered

firm is always in a dry condition.

8. Stabilisers

a) The functions of stabilizers is to prevents the formation of

foam.

b) In an automatic washing machine, excessive foam can

stop the pump working. So, washing powders for

automatic washing machine are made using detergents

that are good at removing and emulsifying grease, but do

not produced foam.

9. Perfumes

Perfumes are added to make clothes smell fresh and clean.

FOOD ADDITIVES

Food additive Food additive is any substance that is added to food in small

quantities to preserve or improve its flavour and appearance.

Uses of food additivesTo make food last longer (to extend the shelf life)To make foods taste better and look better

The rationale for the use of food additives.

To make sure that certain food remains edible throughout the

year.

Types of food additives

Preservatives: sodium nitrite, sodium benzoateAntioxidant: ascorbic acidFlavouring: Monosodium glutamate(MSG), aspartameStabiliser and thickener: gelatin and acacia gumDye: azo compounds, triphenyl compounds

Effects on health

Allergy: MSGCarcinogenic: NaNO₂Brain damageHyperactivity

Functions of food additives

Preservatives: to inhibit or prevent the growth of moulds, yeast and bacteria that spoil foodsAntioxidants: to prevent spoilage of food due to oxidation by oxygenFlavouring agents: to enhance the taste of foodStabilisers and thickeners: to improve the texture of foodsColouring agents: to restore the colour or to enhance the natural colour

A considerable number of food is harvested seasonally. In

such cases preservatives are added to make sure that they do

not get spoilt, and remains edible after along time.

Additives such as vitamins B, C, and D, and minerals such as

iron is added to improve the nutritional value of foods which

may be destroyed during food processing.

Food additives are used as an artificial sweeteners for diabetic

patients.

Food additives such as potassium iodide in table salt is used

to reduce the incidence of goiter.

The use of food additives such as vitamin C in fruit juices

prevents scurvy, vitamin D in milk and vitamin A in margarine

prevent rickets.

The effects of food additives on health and the environment.

Additives in food should be limited. This is because all the

additives used are chemicals, and over a long period of time

they may have adverse effects in our body. Moreover, no

additive has been proven to be 100% safe. Scientific

knowledge should be applied in the management of food

additives.

Example:

o The excessive use of the flavouring agent monosodium

glutamate (MSG) is harmful, because it causes headaches,

poor vision and dries up the throat, giving rise to unnatural

thirst.

o Food additives such as sodium sulphite, MSG and some

food colours can cause allergic reactions in some people.

o Food additives such as sodium nitrate is carcinogen.

o The excessive intake of nitrites over a long period can

cause brain damage.

o Food additives such as tartrazine can cause hyperactivity.

The functions of food label.

To let the consumers know about the nutrient content, food

additives used, expiry date, halal or non-halal, whether

containing any permitted or prohibited chemicals or whether

the food is good or bad for health.

Life without food additives.

Food spoilage occurs. Food supplies will be reduced and there

will be food shortage around the world.

Deficiency of vitamins and minerals in foods because the

nutritional value of foods may be destroyed during food

processing.

Malnutrition happens especially among the younger

generation due to the loss of appetite because foods do not

look attractive, do not taste delicious or smell good.

Medicine

Drugs

Chemical compounds that are used as medicine to heal any sort

of ailment is known as drugs

Traditional medicines

Traditional medicines are derived from mostly different types of

plant parts or animal parts. They are generally less harmful over

a long period of time when compared to drugs.

Examples of traditional medicine and their uses.

The types of modern medicine, their examples and functions.

PlantLocal nameUsesAloe veraLidah buayaSap used to relieved pain from burnsBetelSirehLeaves relieved sore

eyesBitter gourdPeriaFruit used to cure diabetesCoconutKelapaYoung coconut water reduces

feverGarlicBawang putihReduces infection and hypertensionGingerHaliaReduces inflammation and

improves blood circulation and digestionGinsengGinsengRoots maintain good

healthHibiscusBunga RayaLeaves relieves headache and hair lossTurmericKunyitCures pimples

Type of modern medicineFunctionExamplesAnalgesicsRelieve painAspirin, paracetamolAntibioticsKill or inhibit

growth of infectious bacteriaPenicillin, streptomycinPsychotherapeutic medicinesControl

symptoms of mental illnessStimulants, antidepressants

Side effects of medicines

Both traditional and modern medicines have side effects

Some traditional medicines help people lose their weight by

speeding up their metabolism. The side effects are an increase in

blood pressure and heart rate

Birth control pills are an example of modern medicine. Women

who use them experience side effects such as hypertension,

acne, and abnormal bleeding.

Correct ways of using medicines

Use the correct amount or dosage and using it for the correct

purpose

For example, using antibiotics to treat infections caused by

viruses is drug misuse. This is because antibiotics have no effect

on viruses.

Drug abuse is using drug for its intoxicating effect. For example,

the use of Morphine, Viagra and ecstasy pills.

The significance of chemicals in the world today and its side effects.

Chemical have become an integral part of today’s lifestyle.

Each and every toiletry, cosmetic, or food that we use or

consume is some way or the other related to chemicals. From

the moment we get up from bed, the toothpaste we use to

brush our teeth, the soap, the shampoo and detergent that

we use and the breakfast cereal that we eat have some form

of chemical or other.

However, chemicals are not 100% organic friendly. For this

reason, before eating preserved food we should think whether

we can possibly replace it with some other organic food, or

while using cosmetics or toiletries, we should choose the ones

that have reduced chemicals.

A life without chemicals is impossible. Hence, it is up to us to

use them wisely and sparingly.

NAMA : NUR FARAH ATHIRAH BINTI RODZINO. MAKTAB : 409/050

GURU : PUAN SURIA