chapter 13 chemicals for consumers

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CHAPTER 5

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CHEMICAL FOR CONSUMERSCHEMICAL FOR CONSUMERS

A.A. Soap and DetergentSoap and Detergent

B.B. Food AdditivesFood Additives

C.C. MedicineMedicine

D.D. The Existence of ChemicalsThe Existence of Chemicals

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(A)

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Learning OutcomesLearning Outcomes1. State what soap is

2. State what detergent is

3. Describe soap preparation process

4. Describe detergent preparation process

5. Describe the cleansing action of soap

6. Describe the cleansing action of detergent

7. Compare and contrast the effectiveness of cleansing action of soap and detergent

8. Identify the additives in detergent and their respective functions

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What is soap?What is soap?• Soaps are sodium or potassium salts of long-

chain fatty acids.

• General formula of a soap can be written as: RCOONa+ or RCOOK+

• R is an alkyl group that usually containing 12 to 18 carbon atoms. R can be saturated or unsaturated

• Soaps are prepared through saponification

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Formula of soap

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SaponificationSaponification• Saponification is a process to prepare soap.

• Soap is made by boiling a mixture of fats or vegetable oil with concentrated alkali (NaOH or KOH)

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What is detergent?What is detergent?• Detergent is non-soap cleansing agent. • Detergent is the sodium salt of sulphonic acid

• It is divided into natural detergent and synthetic detergent

• Natural detergent is made from animal or vegetable oil while synthetic detergent is normally made from petroleum

• Commercialized detergent are usually sodium alkyl sulphate and sodium alkyl benzene sulphonate

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Formula of detergent

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Comparison of Soap and Detergent

Soap Detergent

Strength

Biodegradable Not poisonous to

aquatic life

effective in hard water and acidic water

Weakness Not effective in hard

water and acidic water

not biodegradable

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The cleansing action of soap and detergent

• The cleansing action of soap and detergents results from their ability to lower the surface tension of water.

• This ability is due to the structure of soaps and detergents.

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The structure of soaps and detergent

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The structure of soaps and detergent

Soluble in oils or grease

Soluble in water

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Cleansing Action of Soap and DetergentCleansing Action of Soap and Detergent

1. Soap reduces the surface tension of water.

2. This increase the wetting ability of water.

3. So, the surface of cloth is wetted thoroughly.

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1. The hydrophobic part of the soap anion dissolves in the grease.

2. The hydrophilic part attracted to the water molecules.

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1. Scrubbing helps pull the grease free from cloth surface.

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1. Grease is removed from the cloth surface as tiny oil droplets.

2. Tiny oil droplets with negative charge repel each other.

3. This prevent them from redeposit on the surface.

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Cleansing Action of Soap and DetergentCleansing Action of Soap and Detergent

Aim : To compare and contrast the effectiveness of cleaning action of soap & detergentApparatus : 250cm3 beakers, 100cm3 measuring cylinder, glass rodMaterial : detergent & soap solution , soft water, hard water ( distilled water + MgSO4 ), pieces of cloth (2cm x 2cm) with oily stain

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Procedures:1. Prepare 4 beakers with the content below:

2. Stir the solution in each beaker using a glass rod until no changes can be observed

3. Record all changes that occurred4. Place a piece of cloth with oily stain into each beaker.5. Wash the oily stain on each piece using the solution in each

beaker and stirred6. Observe and record whether the oily stain on each piece of

cloth dissapear.

Exp Content

I 100cm3 of soap solution

II 50cm3 of soap solution + 50cm3

MgSO4

III 100cm3 of detergent solution

IV 50cm3 of detergent solution + 50cm3

MgSO4

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Result:

Conclusion: Soap solution was an effective cleansing agent in soft

water but not in hard water. Detergent solution was effective in both solution.

Exp Observation

I A lot of lather was formed. The oily stain was removed. The cloth was clean

II No lather but white precipitate was formed. The oily stain remained on the cloth.

III A lot of lather was formed. The oily stain was removed. The cloth was clean

IV A lot of lather was formed. The oily stain was removed. The cloth was clean

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Additives in detergent

Additives Function

biological enzymes To remove protein stains such as blood

fragrances To add fragrance to both the detergent and fabrics

whitening agents To convert stains into colourless substances

suspension agents To prevent the dirt particles removed from redepositing onto cleaned fabrics

foam control agents To control foaming in detergent

builder To enhance the cleaning efficiency of detergent by softening the water

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(B)

FOOD ADDITIVES

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FOOD ADDITIVES

• A natural or synthetic substance which is added to food to prevent spoilage or to improve its appearance, taste or texture

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Types of food additives

1.1. PreservativesPreservatives

2.2. AntioxidantsAntioxidants

3.3. Flavouring agentsFlavouring agents

4.4. StabilizersStabilizers

5.5. Thickening agentsThickening agents

6.6. DyesDyes

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PreservativesPreservatives

Are substances added into food to slow down or prevent the growth of microorganism such as bacteria, fungi or microorganisms.

Food can be kept longer.

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Examples of PreservativesExamples of Preservatives

PreservativesSodium nitrite,

NaNO2

Functionto preserve and stabilize the red colour in meats.

Found infrozen meat, canned meat, sausages and burger

Negative effect

Cause stomach cancer because the nitrites produces carcinogenic nitrosamines

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Examples of PreservativesExamples of Preservatives

Preservatives

Benzoic acid, C6H5COOH

Sodium benzoate, C6H5COONa

Functionto prevent the growth of bacteria

Found inFruit juice, chili sauce, tomato sauce, oyster sauce, soy sauce

Negative effect

Usage in great amount will damage the nervous system.

Allergic to some people

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Others Preservatives

Preservatives Function and Examples

Salt

Draws out water from the cells of microorganism and retards the growth.

Found in salted fish, salted eggs, salted vegetables, ham and bacon

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Others Preservatives

Preservatives Function and Examples

SugarDraws out water from the cells of microorganism and retards the growth.

Found in jelly, fruit jams and pickles fruit.

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Others Preservatives

Preservatives Function and Examples

VinegarProvide acidic medium that prevent the growth of microorganism

Found in pickled fruits, chili and vegetables

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Others Preservatives

Preservatives Function and Examples

Sulphur dioxidePrevent the growth of microorganism

Found in soft drinks and sauces.

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Antioxidants

Antioxidants are added to prevent oxidation of

fats and oils.

Oxidation of fats and oils in food cause it to

become rancid.

Oxidation of fruits causes brown fruits.

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• Examples :

» ascorbic acid (vitamin C)» tocopherol (vitamin E)» sodium citrate» butylated hydroxyanisole (BHA)

» butylated hydroxytoluene (BHT)

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Examples of food contains Antioxidants

Food contains antioxidants are :

cakes, biscuits, margarine, deep fried food, vegetable oil.

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Flavourings

flavourings are used to improve the taste of food

and restore taste loss because of processing.

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• Examples of flavourings are

• sugar, salt, vinegar, • Monosodium Glutamate (MSG) ,• Aspartame, • synthetic essences mostly ester

Examples :

- pentyl ethanoate (banana flavour) - ethyl butanoate (pineapples flavour) - octyl ethanoate ( orange flavour)

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Stabilizers

Stabilizers helps to prevent an emulsion from separating out.

Examples of stabilizer are

Lecithin,

Mono-glyceride of fatty acids

Di-glyceride of fatty acids

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Stabilizers Stabilizers are used in margarine, butter, ice

cream and salad cream (mayonnaise, thousand island etc)

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Thickeners

Thickeners are often added to food to alter the texture of food (thicken foods)

Examples

Starch - used in instant soup and puddings

Pectin - used in making of jams and jelly

Acacia gum - used to thicken chewing gum, jelly and wine

Gelatine – used in yogurt

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Food Dyes

Food Colouring are dyes.Food Colouring are dyes.

Food dyes are used to add or restore the colour Food dyes are used to add or restore the colour in food due to food processing.in food due to food processing.

Food Dyes are normally azo compounds or Food Dyes are normally azo compounds or triphenyl compoundstriphenyl compounds

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Tartrazine a yellow dyes from azo compound

used in orange drinks, custard powder, sweets and apricot jam

Is believed to cause hyperactivity in children

Brilliant Blue FCF blue triphenyl dye

used in sweets

Anthocyanin Found naturally in red grapes, red cabbages and sweet potatoe

contains antioxidant properties

Examples of Food Dyes

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Effect of Food Additives on Health

Food Additives Harmful Effects

Sodium nitrite Can cause cancer

Sodium benzoateAffect nerve function

Cause allergy

TartrazineCan worsen the condition of asthma patients

Cause hyperactivity in children

Colouring substance eg.Amaranth, sunset yellow, ponceau 4R

Cause cancer, migraine, allergy and deformity of babies

Monosodium Glutamate

Cause health problem form long term used like headaches, difficulties in breathing, vomiting

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Medicines

Can be classified as

1. Traditional Medicines

2. Modern Medicines

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Medicines

Traditional Medicine Modern Medicine

Aloe VeraCentella Asiatica

(Pegaga)

Eurycoma Longifolia(Tongkat Ali)

Orthosiphon Aristatus(Misai Kucing)

Analgesics

Antibiotics

Andrographis Paniculata(hempedu bumi)

Ocimum basilicum(Selasih)

Psychotherapeutics

Cocaine Quinine

Ginger

Garlic

Mint(Pudina)

Lemon/ Oranges

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Aloe Vera(lidah buaya)

to treat skin wounds

Centella Asiatica(Pegaga)

to treat depression & for longevity(longlife

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Eurycoma Longifolia(Tongkat ali)

to increase the male libido(nafsu)

Orthosiphon Aristatus(Misai kucing)

to treat gout, diabetes and rheumatism

(sakit sendi/tulang)

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Andrographis Paniculatahempedu bumi

to treat diarrhoea, fever and diabetes

Ocimum basilicumSelasih

to treat coughs, colds and bronchitis

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Coca plantto produce

cocaine(drug) as pain killer

Quinine from Cinchona plant

to cure Malaria

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Ginger (halia)for stomach pain due to

wind in stomachfor keeping body warm

for preventing flu attack

Mint (pudina)to increase body temperature

for sweating

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Garlicfor preventing flu attack

or asthma attackfor reducing high blood

pressure

Lemon/orangefor preventing flu attack

for treating skin diseases

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Kacip Fatimahleaf decoction drunk for

dysentery(intestinal infection)

Lemon grasspound leaf apply to forehead for curing

headache

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Modern Medicines

• Classified into 3 main group

1. Analgesics

2. Antibiotics

3. Psychotherapeutics

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Analgesics• Medicines to relieve pain.

Examples of analgesics

AspirinTo relieve pain

& anti-inflammatory

ParacetamolReduce fever & relieve pain

CodeineRelieve minor to moderate pain

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Antibiotics

• Medicines that destroy or prevent the growth of microorganism

Examples of antibiotics

Penicilin to treat pneumonia,

gonorrhoea & syphilisStreptomycin

To treat tuberculosis(TB)

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Psychotherapeutic

• For treating mental or emotional illness.

• Can be divided into 3 main group:

– STIMULANTS– ANTIDPRESSANT– ANTIPSYCHOTIC AGENTS

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Psychotherapeutic Psychotherapeutic MedicinesMedicines

StimulantsDrugs that stimulate the activity of brain

& central nervous system

AntidepressantMedicines that reduce Tension and anxiety

Antipsychotic AgentHelp a person to

live a more normal life

ExamplesCaffeine

amphetamines

Examplesprozac

Exampleschloropromazin

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Side Effects of Modern Medicines

Medicines Side Effects

aspirin

Can cause bleeding in the stomach because it is very acidicCan cause allergic reactions, skin rashes & asthmatic attacks

penicillinCan cause allergic reaction which may be fatal

amphetamines

People abuse amphetamines are excitable & talkativePsychologically addictive & can cause heart attackCan cause anxiety, sleeplessness, aggressive behaviour and decrease appetite

codeine Cause addiction

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Side Effects of Modern Medicines

Medicines Side Effects

streptomycin

Cause nausea, vomiting, dizziness, rashes & feverCause loss of hearing following long-term use

stimulants Can cause addiction

antidepressants

Can cause addictionCan cause headaches, grogginess & loss of appetite

Antipsychotic drugs

Can cause dry mouth, blurred vision, urinary retention, constipationCan cause tremor and restlessnessSedation (make people calmer or sleepy)