7/28/2019 Form 5 Chap 5

1/19

SOAP & DETERGENT

I)

o

Definition of Soap

Soap are or salts of long-chain carboxylic

o

acidsThe general formula of a soap :RCOO Na / RCOO K

R is an group which contain to carbon atoms.

II) The history of soap manufacturing. Process ofmaking soapashes orsodium

Babyloniansmade soap

around 2800

B.C.

Purifying oils is recorded onHebrew Tables around 4000 B.C.Ash + LimeCaustic potash

Caustic Potash + fats

soap

carbonate from common

salt is patented byNicholas Leblane

(French).

Michel Chevreul (French)

discovered animal fats are

cmposed of fatty acids andglycerol ( Causes rapid

development of soap &

candle.)

Sodium carbonateNa COis produced cheaply &

used forglass making ,

soaps and detergent.

After 20 years, Ernest

Solvay ( Belgian Chemist)

developed Solvay process.

Later on, vegetables oil isused to replace animal fats.

Solvay Process

- ( obtained from heating CaCo ) is passed into

concentrated NaCl solution which is saturated with ammonia .

NaCl +NH +H O + CONa HCO +NH Cl- NaHCO is then heated to obtain soda.

2NaHCONa CO +H O +CO .

1

7/28/2019 Form 5 Chap 5

2/19

2

III) Preparation of Soap by Saponification

Saponificationisaprocess whereby

It is also the alkaline of using alkaline solutions.

(Fats- tallow from cow)( Vegetable oilspalm oil or olive oil)

For example,- Glyceryl tristearates

is a naturally occuring esters

found in fats or oils.

Example of soap,1) sodium palmitate, C H COONa

2) Sodium oleate, C H COONa

3) Sodium stearate, C H COONa

To enhance the soaps marketability,additives are used such as perfume,colouring matter and antiseptic.Production of soap can be precipitated by adding common salt to the

reaction mixture in order to reduce the solubility of soap in water.

Properties of soap depends on

a) type of used for saponificationb) type of or vegetable oils used

7/28/2019 Form 5 Chap 5

3/19

3

Potassium soap are softer, milder than sodium soap which can be used for

bathing.

IV) Structure of soap molecule.

When soap is dissolved in water, it will dissociate and produce sodiumions and ions.

The active substances in soap is carboxylate ions which consists two

parts:

a) the Head

1. charged

2. contains theCOion

3. is ( like to dissolves water)

b) the Tail

1. charged2. is a long chain

3. is ( do not like to dissolves water)

I ) Definition of Detergent

Detergentisa

.

It is a kind of .There are 3 types of detergent which depends on the charge on detergent ion.

a) Detergent.Head of the detergent particle contains a negatively charged ions.

Example : ROSO NaDivide into two types:

( detergent molecule with a benzene ring)

R - - SO Na R SO

7/28/2019 Form 5 Chap 5

4/19

4

Sodium alkyl sulphate Sodium alkylbenzene sulphonates

- can be prepared from alcohols with chainlengths of 12 to 18 carbon atoms.- Step 1:Reaction with Concentrated

Step 2 :

Neutralisation with sodium hydroxide solution

Starting materials- long chain alkene, RCH = CH , obtained fromthe cracking of petroleum.

Step 1 : ( introduction of the alkyl group to

an organic molecule)

Step 2 :

( introduction of the sulphonicacid group to an organic molecule to form

sulphonic acid)

Sodium alkyl sulphate ( without a ring)

ROSOb) Detergent

Head of the detergent particle contains a positively charged ion.Example : RN(CH ) Br

c) detergent

Example : ROCH CH OH

II) Preparation of Detergent

7/28/2019 Form 5 Chap 5

5/19

5

III) The Structure of Detergent Molecule

When a detergent is dissolved in water, it dissociates to form ions

and ions.

It consists of two parts:a) the Head ( group, - OSO / group - SO)

1. charged2. ( like water)

b) the Tail ( long hydrocarbon chain)1. neutral

2. hydrophobic ( hates water)

ThecleansingactionofsoapanddetergentThe cleansing action of soaps and detergent results from

the ability to the surface tension of water,to oil/ grease and

to hold them in in water

This can be occurred due to their and the .

Oil cannot be washed away from clothing with water only as it is a covalent

molecule which is insoluble in water.

1. sodium soap dissolves in water to form soap (-ions) and sodium (+ions).2. Anion consists of a long hydrocarbon chain with a carboxylate group on one end.3. the hydrocarbon (hydrophobic)soluble in oil/ grease.4. carboxylate group (hydrophilic) soluble in water.

Process of the cleaning action of soap and detergent.

- A piece of cloth is stained with grease and then dipped into soap/ detergent water.- Through this, the ability of water increases. Thus, the surface of cloth is wetted

thouroughly.

- The part of the soap/ detergent anion dissolve in grease while the hydrophilicpart is attracted to molecule.

- Because of the forces of attraction between molecules and -chargedheads, the grease begins to be lifted off the surface when the water is agitated slightly.- agitation during scrubbing helps the process of emulsfication occurs whereby

the grease is broken into small droplets.

- The droplets do not and on the surface of the cloth due to therepulsion between the charges on the surface. These droplets are suspended in

water to form . The droplets is rinsed and washed away and leave the surface

clean.

7/28/2019 Form 5 Chap 5

6/19

6

7/28/2019 Form 5 Chap 5

7/19

7

Additives Function Example

Builders To enhance the efficiency of

detergent by the water.To increase the value of water.

Sodium tripolyphosphate

Drying agents To ensure that the detergent in powdered form

is always in condition.

To add to the bulk of the detergent and enable topour it at ease.

Sodium sulphateSodium silicate

Fragrances To add to both detergent and fabrics.

Foam control agents To control in detergent.

Optical whitener To add and whiteness to

white fabrics.

Fluorescent dyes

Suspension agents To prevent dirt particles removed from

onto cleaned fabrics.

Carboxymethylcellulose(CMC)

Biological enzymes To remove stains such as blood.To break down and protein molecules

in food stains.

Amylases ,proteases,

cellulases and lipases

Whitening agents To convert stains into substances.To make the fabrics whiter and more beautiful.

Sodium perborate

Sodium hypochlorite(NaClO)

V) The effectiveness of soaps and detergents as cleansing agents

Cleansing

agents

Advantages Disadvantages

Soap 1. very effective in soft water to wash

clothes.( water does not contain Mg & Ca

ions)2. Do not cause pollution as soaps aremade from fats and oils and can be

decomposed by the action of bacteria.

1. Ineffective in hard water.2. A grey scum (Magnesium stearate &

calcium stearate) will be produced in hardwater

3. Not effective in acid water.( exist as

molecules & do not have hydrophilic ends)

- H ion from rainwater (acid) will react

with soap ions to produce carboxylic acidmolecules of large molecular size that areinsoluble in water. Example

7/28/2019 Form 5 Chap 5

8/19

8

Detergent 1. effective in soft water and hard water.

( magnesium salt and calcium salts are

formed aand soluble in water)( scum is not formed)2. Synthetic cleansing agents

- structure of hydrocarbon chain can bemodified to produce detergent.3. effective in acidic water as H ions is

not combine with detergent ions.

1. non-biodegradable2. water pollution occurs.

3. Decrease in oxygen content in water and

the aquatic lives are given the harm.(phosphates in detergents)

4. a lot of foam will be produced in waterthat prevent oxygen from dissolving inwater.As a result, fish and other aquatic

lives face the death.

5. Additives (sodium hypochlorite )

releases chlorine gas that is highly toxicand kills aquatic life.

7/28/2019 Form 5 Chap 5

9/19

9

B) FOOD ADDITIVES

- Definition of Food Additivesare natural or synthetic substance which are

added to food to:i)

ii)

iii)

iv)v)

.- Type of Food Additives and Their Functions

1. substance added to food to slow down and prevent

the growth of microorganisms in order to kepp the lasts longer.

- salts, vinegar and sugar have been used for centuries to preserve food.

Preservatives Molecular

Formula

Uses

Saltsugar

water out of the cells of microorganismsthe growth of microorganisms.

Vinegar Provides condition that the

growth of microorganisms.

Sodium nitriteSodium nitrate

NaNO

NaNO

To the meat, sausage, cheese and dried

fish. To prevent food in canned food.

To maintain the colour ofmeat. To make the meat look fresh.

C H COOH

C H COONa

To preserve sauces, fruit juice, jams and margarine.

Sulphur

dioxideSodium

sulphate

SO

Na SO

Used as to prevent browning in fuits.

Maintain the colour and freshness of vegetables.To prevent thr growth of .

2. Antioxidants- added to food to

i) pevent oxidation that causesfats and foods

ii) to slow down the process.- food containing fats or oils are oxidised and become rancid when exposed

to air. This makes the food unpalatable. Th rancid products are volatileorganic compounds with 4 odours.

7/28/2019 Form 5 Chap 5

10/19

10

( exp : butanoic acid, C H COOH)

Antioxidants Uses

Butylated Hydroxyanisole (BHA)

Butylated Hydroxytoluene (BHT)Sodium citrate

Vitamin C

Stimulates the immune systems.

Preserve the colour of friut juice.

Vitamin E Reduce the risk of heart diseases and cancer.

3. Flavourings

- Flavourings are the largest group of food additives.- Function : to improve the taste of food restore taste loss due to processing.

- There are 2 types of flavourings :i)

- Flavor enchancers are chemicals that are added to food to bringout the flavours/ to enhance the tastes of food.

- Exp : monosodium glutamate (MSG)MSG is a sodium salt of .

It exists as solid fine white crystal.It is added to savoury prepared and processed

- frozen foods- spice mixes

- canned and dry soups- salad dressings

- meat and fish based products

In order to protect the public health, MSG is not allowed in baby

foods and less used for the adults.

ii)

Aspartame

-Aspartame is a , odourless powder, approximately 200times sweeter than sugar.

-It is used in a variety of foodstuffs.

7/28/2019 Form 5 Chap 5

11/19

11

- It is when dry or frozen but breaks down and loses itssweetness over a time when stored in liquids at temperature above

30.Exp : diet drinks and soft drinks

- Synthetic Essences

o

contain which are made to resemble natural flavour.o Exp :pentyl ethanoate, CH COOC Hgive banana flavour and is

cheaper to use.

- Many of compounds are used to produce artificial flavours belong to the

homologous series of esters.

4. Stabilizers

- a substance which helps to prevent on ( oil /waterdroplets suspended in water/oil droplets) from separating out.

- It is used in margarine, butter, ice cream and salad cream.

- exp : lecithin, mono- and di-glycerides of fatty acids.

5. Thickeners

- are chemicals that are added to food to the liquid and to prevent thefood from .

- They absorb water and thicken the liquid in food to produce a jelly-likestructure.

- They are natural .

- Exp:

Thickeners ExplanationUsed in instant soups and puddings.

Used in jams and jellies.Forms a firm jel when there is sufficient sugar in amixture.

Is not digested.

Can be considered as a beneficial and dietary fibre.

To thicken chewing gum, jelly and wine.

To thicken yogurt.

6. Dyes

- chemicals that are added to food to give the colour so as to improve theappearance of food.

- is used to add or restore the colour in food in order to

- enhance its visual appeal

- match consumer expectations

7/28/2019 Form 5 Chap 5

12/19

12

- give colour to food that have no colour.

- artificial food dyes are oftenly used

- they are more uniform, less

- many food dyes are

i) compounds ( red , orange,yellow)- orang drinks, custard powders, sweets and apricot jam.

iii) compounds( blue-brilliant blue FCF, green)

- main trend in colour of food towards the use of natural colours is .* found in red grapes, red cabbage sweet potatoes

* have antioxidants properties.

Effect of Food Additives on Health.

Effects Explanation

Allergy Caused by Sodium sulphite, BHA and BHT , MSG

and food dyes( yellow No.5).

Cause an diseases named

(giddiness, chest pain and difficulty in breathing)

Cause diseases occuring on babieswhich iits synptoms is lacking of oxygen and the

presence of sodium nitrate /nitrite.

Cancer Caused by (sodium nitrite)

Nitrite reacts with amines to produce (cause cancer)

Brain damage Caused by excessive intake of .

Hyperactivity Caused by tartrazine (additives)

Difficul to sleep or relax and felt restles.

The Rationale for Using Food Additives

To prevent food

spoilage.Advantages To improve

nutritional value

Medical reasons

7/28/2019 Form 5 Chap 5

13/19

13

Life without food

additives

Food spoilagealways occur

Diseases will occur

oftenly

Malnutrition willoccur particularly.

C) MEDICINE

- medicine is a substance used to prevent or cure or to reducepain and suffering due to .- it is classified as

i) traditional medicine

is a medicine derived from natural resources without being

processed chemically.

Can be obtained from and animals.

Any medicinal plant containing is potentially toxic

to liver.

Some of it interacts with medications resulting in serious sidereactions.

Exp : garlic capsules combined with diabetes medication can

cause a sudden decrease in blood sugar

7/28/2019 Form 5 Chap 5

14/19

7/28/2019 Form 5 Chap 5

15/19

ii) Modern Medicine

they usually contain a mixture of active ingredients prepared in differentforms such as capsules, pills, solution and suspensions.

Exp: (used as antacid) contains sodium bicarbonate (NaHCo), citric acid and aspirin to neutralises the excess stomach acid.

can be classified as follows based on their sffect on the human body :

a) (painkillers)

medicines that relieve pain without causing numbness or affectingconsciousness.

Analgesics Uses Side effect

Aspirin

o Reduce fever

o Relieve headaches,

muscle aches and joint

aches.

o Treat arthritiso Acts as an

anticoagulant

prevent clotting blood.

o Reduce the risk of

heart attack andstrokes.

Cause brain and liver

damage of illed-

children.

Cause bleeding in the

stomach.

Cause allergy

reactions, skin rashes,

asthmatic attacks.

Paracetamol

neutral

o To relieve mild to

moderate pain(headache,muscle and

joint pain, backache ,period pains)

o Does not irritate the

stomach to bleed.

Causes skin rashes,

blood disorders and

acute inflammation

of the pancreas.

Cause liver damage.

Codeine Cause addiction,

depression, nausea,drownsiness

7/28/2019 Form 5 Chap 5

16/19

Is a nacortic drugs.

Is a strong analgesics.

7/28/2019 Form 5 Chap 5

17/19

b) antibiotics

Cemicals that destroy / prevent the growth of infected microorganisms.Will not cure the infection caused by viruses such as cold and flu.

Obtained from bacteria/fungi.

Broken down by acid in the stomach.

Antibiotics Uses Side effects

Penicillin

Derived from the

mould penicilliumnotatum

o Treat diseases

caused by bacteria

such as oneumonia,

gonorrhoea, syphilisand tuberculosis.

Cause allergic

reactions

Cause daeth for

people who

allergiuc at it.

Streptomycin

Produced by soil and

bacteris at the genus

streptomyces

o Treat tuberculosis,

whooping cough

and some formsof pneumonia.

Cause

nausea,vomitng,

dizziness, rashes

and fever.

Loss of hearing

following long

term use.

c) psychotherapeutic medicines.

A group of dugs for treating mental / emotional ilness.

Psychotherapeutic medicines Uses Side effects

StimulantsA medicine which activates thelevel of arousal and alertness of

the central nervous system to

reduce fatigue and elevate moon

in most people.

i) AdrenalineA need in demanding energeticactivities.

ii) caffeine

weak, naturally occuring stimulant

found in coffee, tea and cola drinks.iii) Amphetamines

Strong synthetic stimulants

Increase alertness & physicalability.

Increase the heart *repiration rates

& blood pressure.

Cause addiction

7/28/2019 Form 5 Chap 5

18/19

AntidepressantsMedicine used primarily in the

treatment of depression.

i) tranquilizersto clam down a person

reduce tension & anxiety

cause drowsiness, poorcoordination and light

headedness, respiratory

difficulties,sleeplessness, coma and

death if overdose.

i) BarbituaratesTo sedate, calm and relax individual

in low doses.

Cause sleep (high dose)

Cause addiction and

habit formingCause death.

Antipsychotici) chlorpromazine

ii) haloperidoliii) clozapine

To treat psychiatrie illness such asschizophrenia(loses touch with reality)

Cause mild, dry mouth,

blurred vision, urimary

retention, constipation,

tremor and less rrest as

well as sedation(more

clmer/sleepy)

! Drug Abusetaking drugs excessively and without a doctors

prescription.the examples of drugs are ectasy and ice.

D) THE EXISTENCE OF CHEMICALS

The chemicals for consumers such as soap, detergents , food additives andmedicineplay an important role in our life . However, they can contribute

negative effects to our health and the environment if these chemicals are

not used wisely .

Some proper management of these chemicals :-

Detergents

Wear gloves when working with strong detergents to protect your hands .

Use biodegradable detergents .

Use appropriate amounts of detergents.

Food additives

Be wise when we consume the food with food additives. Avoid consuming too much salt and sugar .

Avoid foods with additives which you are sensitive to .

Avoid rewarding children with junk food .

Medicines

No self medication .

Do not take medicine prescribed for someone else .

7/28/2019 Form 5 Chap 5

19/19

Check for expiry date .

Follow your doctors instruction for taking medicine . Keep away from children .

Do not overdose .

Intensive scientific research must be carried out to produce new substances

and this takes more time . Scientists must patient and persevere for theirresearch and development to produce new chemicals in future .