form 5 chap 5
TRANSCRIPT
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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 .
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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
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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
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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
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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.
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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
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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.
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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.
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( 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.
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- 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
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- 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
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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
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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
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Is a nacortic drugs.
Is a strong analgesics.
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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
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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 .
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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 .