Download - Chemicals for consumers
CHEMICALS FOR CONSUMERS
FORM 5 CHAPTER 5
By : Iskandar Zulqarnain Mohd Ishak (5B)
5.1 Soaps & Detergent
Soaps are sodium or potassium
salts of long-chain fatty acid.
General formula of a soap can be written as or
R is an alkyl group usually contains 12 or 18 carbons atoms. R can be saturated or unsaturated
PREPARATION OF SOAPS1. Soaps are prepared by the alkaline hydrolysis (saponification) of
vegetable oils and animal fats.
2. When oils or fats is boiled with concentrated sodium hydroxide solution, soap and glycerol are formed.
3. Sodium chloride is added to the soap mixture to cause precipitation of soap. The role of this NaCl is to reduce the solubility of soap in water.
DETERGENT• Detergents are made of synthetic cleansing
agents such as petroleum fractions. E.g. :
PREPARATION OF DETERGENTS(sulphonation)
The Cleansing Action of Soaps & Detergents•Both soaps and detergents have an ionic head and tail consisting of a long hydrocarbon chain.
•The ionic head is negatively-charged. It is hydrophilic which is soluble in water.
•The long hydrocarbon tail is hydrophobic which is soluble in oil but insoluble in water.
PROCESS OF CLEANSING
THE EFFECTIVENESS OF SOAPS & DETERGENTS
Soaps Detergents
Form scum (insoluble precipitate) in hard water. reduces amount of
soap for cleaning thus cause wastage
Does not form scum in hard water and also in acidic water. This means detergents are more effective than
soapBoth soaps and detergents do not form scum in soft water. Soft water is
water that contains little or no and . Hard water is vice verse.THE EFFECTIVENESS OF SOAPS IN ACIDIC WATER IS REDUCED
SOAPS
THE ADDITIVES IN DETERGENT
Amylases, proteases, lipase
Sodium tripolyphosphate
Fluorescent dyes
Sodium perborate
Cleaning agent
Soap Detergent
Effectiveness Effective cleaners in soft water
Effective cleaners in soft and hard water
Formation of scum
Yes No
Sources Natural resources (animals fats or vegetable oils)
Synthetic resources (petroleum fractions)
Formation of precipitate
Yes in acidic water No in acidic water
Effect on the environment
Biodegradable and not cause pollution
Non-biodegradable and gives thick foams that can kill aquatic lives
COMPARISON TABLE BETWEEN SOAPS & DETERGENTS
5.2 Food Additives
Preservatives Example How it worksSalt Salted fish Draws out water
Vinegar Pickled mango Provide acidic conditionSulphur dioxide Fruit juice Slow down growth of microorganisms
Some food additives can cause high blood pressure, heart attack, stroke, asthma, allergies and hyperactivity.
Antioxidants Example How it worksButylated hydroxyanisole (BHT) Margarine Retards rancidity in oils
Ascorbic acid (Vitamin C) Fruit juice Preserves color
Sodium citrate Cooked cured meat Stop fats turn rancid
Flavorings Example FunctionMonosodium glutamate (MSG) Frozen foods Bring out the flavor
Aspartame (non-sugar sweetener) Diet drinks Sweeten foods
Synthetic essences Pentyl ethanoate
(banana flavor)
Produces artificial flavors which resemble natural
flavors
5.3 Medicine• A medicine is used to prevent or cure a
disease or to relieve pain.• Medicines can be classified into traditional and
modern medicines.TRADITIONAL MEDICINES
Medicinal plant/animal Function
Aloe vera (lidah buaya) To treat skin woundsCentella asiatica (pegaga) To treat depressions and for longevity
Eurycoma longifolia (tongkat ali)
To increase the male libido
Sea cucumber (gamat) To treat Japanese encephalitis and hole in the heart
Ant To treat hepatitis B
modern MEDICINES
ASPIRIN PARACETAMOL CODEINE
for pain relief such as inflammation and dental
pain
Relieve mild to moderate pain such as headaches
and period pain
Used in headaches tablets and cough
medicines
Active ingredient is acetylsalicylic acid
Does not irritate stomach Most of it are synthesized from morphine
Can cause blood disorder and skin rashes if taken
for a long time
May cause drowsiness
Acidic. Cause brain damage. Never give to
children.
Overdosed paracetamol can lead to liver damage
Abuse of codeine may lead to addiction and
nausea
Penicillin Streptomycin
Extracted from the fungus, Penicillium notatum
Produced by soil bacteria,Streptomyces
To cure bacterial diseases such as tuberculosis (TB), whooping cough, pheumonia
Can be broken down by acid in stomach therefore usually given by injection
Side Effects of Antibiotics
Headache Allergic reaction
diarrhoea
Psychotherapeutic medicine
Function Example Side effects
Stimulant Reduce fatigue and elevate mood
Methylphenidate, amphetamine
High dose can cause hallucinations, anxiety
Antidepressant Reduce tension and anxiety
Tranquillisers Drowsiness, poor coordination. Overdosed intake cause sleeplessness
Barbiturates Cause addiction
Antipsychotic Treat psychiatric illness
Chlorpromazine, haloperidol
Drowsiness, rapid heartbeats
The Existence of Chemicals
Chemical Proper management Detergents • Use biodegradable detergents
• Wear gloves on strong detergents
Food additives
• Read the label to know what you eating
• Avoid rewarding children with junk food
Medicines • No self-medication• Follows doctor’s instruction• Do not overdose• Check for expiry date