soap and detergent, medicine , food additives consumer 2011-edited-2
DESCRIPTION
basic chemistry knowledge on soap, dtergent, food additives, medicinesTRANSCRIPT
CHEMICAL FOR CONSUMERS
What is soap?
A SOAP is the sodium or Potassium salt formed when aFatty acid that contains 12 to 18
carbon atoms per molecule is neutralized by an alkali
The general formula of soap is RCOO – Na + or R COO – K + where R is an alkyl group containing 12 to 18 carbon atoms. R can be saturated or unsaturated hydrocarbons
What is general formula for soap?
iii)State two examples of soap
• Sodium palmitate• Potassium stearate
SAPONIFICATION is a process involves boiling fats or oils with concentrated sodium hydroxide solution or concentrated potassium hydroxide solution
What is saponification?
Explain the preparation of soap as shown in the diagram
• Oil or fat is boiled with concentrated sodium hydroxide to produce glycerol and soap
DETERGENT is the salt formed when an alkyl hydrogen sulphate is neutralized by an alkali
What is detergent?
The general formula of detergents are
where R represent a Long-chain hydrocarbon
State two examples of detergent
• Sodium alkyl sulphate• Sodium alkyl benzene
sulphonate
How is detergent prepared?
• A long chain hydrocarbon obtained from petroleum fractions is converted into organic acid.
• The organic acid is neutralise with NaOH to form detergent.
QUESTION 3
Describe the cleansing action of soap or detergent.a) State 3 abilities of both soap and detergent that enable them to act as cleansing agents
i. Ability to lower the surface tension of water
ii. To emulsify oil or grease, and break them into smaller droplets iii. To hold them in suspension in water, so that they do not redeposit on the surface of the cloth
STRUCTURE OF SOAP PARTICLE
•the organic part •the ionic part
•the hydrophobic part
•the hydrophilic part
• the head part•the tail part
• Which part is soluble in water? Defend your answer
B part because
it is ionic part
• Which part is soluble in grease? Defend your answer
A part because it is covalent part
•Redraw the structure above so that it may look like a tadpole
STRUCTURE OF DETERGENT PARTICLE
STRUCTURE OF DETERGENT PARTICLE
•the organic part•the ionic part
•the hydrophobic part
•the hydrophilic part
• the head part•the tail part
• Which part is soluble in water? Defend your answer
B part because it is ionic part
• Which part is soluble in grease? Defend your answer
A part because it is covalent
part
•Redraw the structure above so that it may look like a tadpole
HOW SOAP /DETERGENT REMOVES DIRT
Describe the cleansing action of soap and detergent
Soap dissolves in water and lowers… …………………… of water. This helps to ………………the cloth better
Surface tension
wet
–The hydrophobic part ( tail part) dissolves
in……………………, the hydrophilic part ( head part) dissolves in water
Grease(dirt)
•
c)………………………………… during scrubbing helps
to loosen the grease and lift off the surface . , and also break the grease into …………………………..
•
Movement of water
Small droplet
d)The droplets do not coagulate and redeposit on the surface of the cloth because ………………………. between the negative charges on the surface.
• These droplets are suspended in water, forming ……………………………….or smaller droplets.
repulsion
emulsion
• ……………………………. washes away these
droplets and leaves the surface clean
Rinsing
d)Compare and contrast the cleansing action of soap and detergents
Property
Soap Detergent
1 sources
Made from ………………
or ………………
Made from petroleum fractions
animal
plant
Property
Soap Detergent
2 Molecular
structure
R – COO – Na +
Where R is
……………
R SO4 – or
Alkyl group
Property
Soap Detergent
3 Effectiveness in
hard water
Forms
…………………with hard
water
Does not
form scum with hard water
SCUM
Property
Soap Detergent
4 Effectiveness
in acidic water
Forms
……………. with acidic
water
Does not
form precipit
ate with
acidic water
INSOLUBLE FATTY ACID
Property Soap Detergent
5 Cleaning power
Less powerfu
l…………… powerful
MORE
Property Soap Detergent
6 Effect to the environment
Biodegradable and
do not cause any
……………
Some detergents are non biodegradable and kill aquatic lives
POLLUTION
What does hard water contains?
• Hard water contains calcium ion, Ca2+ or magnesium ion, Mg2+.
Why do soaps form scum with hard water?
• Soap reacts with calcium ion, Ca2+ or magnesium ion, Mg2+ in hard water to form insoluble salt, called scum
Why is soap not effective in hard water?
• Because formation of scum reduce the amount of soap for cleaning and thus wastage of soap occur.
Why is detergent more effective than soap in hard water?
• Detergent form soluble salt with calcium ion, Ca2+ or magnesium ion, Mg2+ in hard water.
• Therefore the cleaning power is not affected by hard water.
Below are some additives in detergents. Fill in missing words
Additives Functions 1 Drying agents
( such as sodium sulphate, sodium silicate)
to keep the powder……………….
DRY
Additives Functions
2 Builders ( such as Sodium triphosphate)
……………water.
soften
Additives Functions 3 Biological
enzymes( such as amylase, lipase)
to digest
in dirt or to modify fabric feel
PROTEIN, FAT OR CARBOHYDRATE
Additives
Functions
4 Such as sodium perborate
Convert stains into
…………………substances
colourless
Additives
Functions
5 Perfumes Make clothes smell
……………. And clean
fresh
Additives Functions 6. Stabilizers
( such as silicones)
Prevent formation of
………………
foam
FOOD……..
FOOD ADDITIVES
TYPES OF FOOD ADDITIVES
AND FUNCTIONS
FUNCTION TYPE1) IMPROVED COLOUR OF FOOD TO MAKE IT MORE ATTRACTIVE2) SLOW DOWN SPOILING OF FOOD CAUSED BY GROWTH FUNGI OR MICROORGANISMS
DYES
PRESERVATIVES
FUNCTION TYPE3) ENHANCE THE NATURAL FLAVOUR OF FOOD4) PREVENT OXIDATION OF FATS AND OILS SO THAT FOOD DO NOT BECOME RANCID
ANTIOXIDANTS
FLAVOURING AGENTS
FUNCTION TYPE
5) IMPROVE APPEARANCE OF FOOD AND GIVE FOOD A FIRM TEXTURE
STABILIZERS AND THICKENING
TYPES OF FOOD ADDITIVES AND EXAMPLES
EXAMPLES TYPE1) AZO COMPOUNDS
2) SODIUM NITRITE, SODIUM BENZOATE
DYES
PRESERVATIVES
EXAMPLES TYPE3) MONO SODIUM GLUTAMATE (MSG)4) ASCORBIC ACID(VITAMIN C)
5) ACACIA GUM
FLAVOURING AGENTS
ANTIOXIDANTS
STABILIZERS & THICKENING AGENTS
TRADITIONAL MEDICINES
MODERN MEDICINES
a) What is modern medicine?Medicines that are made by scientists in the laboratory
1. ANALGESICS
FUNCTIONS:Relieves pain without affecting consciousness
1. ANALGESICS
EXAMPLES:ASPIRIN – for inflammation such as arthritic pain and dental pain. The active ingredient is Acetylsalicylic acid.
1. ANALGESICS The structure is:COOH
O
C
O
CH3
CODEINE – used in headache tablets and cough medicines
PARACETAMOL – relieves moderate pain
1. ANALGESICS - EXAMPLES
2. ANTIBIOTICS
FUNCTIONS:Kill or inhibit growth of infectious bacteria
2. ANTIBIOTICSEXAMPLES:PENICILIN – to kill bacteria that cause tuberculosis (TB) and pneumonia
STREPTOMYCIN – used to treat whooping cough and pneumonia
3. PSYCHOTHERAPEUTIC MEDICINESFUNCTIONS:Control symptoms of mental illness
EXAMPLES:STIMULANTS – to reduce fatigue and elevate mood e.g. Amphetamine
3. PSYCHOTHERAPEUTIC MEDICINESANTIDEPRESSANT – to reduce tension and anxiety e.g. Tranquilisers and barbiturates
ANTIPSYCHOTIC – to treat psychiatric illness such as schizophrenia e.g. clozapine
WHY SHOULD YOU TAKE FULL COURSE OF ANTIBIOTICS?
•To ensure all the bacteria are killed•the bacteria may become more resistant to the antibiotic. •When this happens, the antibiotic is no longer effective. •a different and stronger antibiotic to fight the same infection is needed
SIDE EFFECTS OF MEDICINES
TYPES OF MEDICINE
MEDICINES
SIDE EFFECTS
Analgesics Aspirin Cause internal bleedingCause brain and liver damage if given to children
Paracetamol
Cause liver damage if taken for a long time
TYPES OF MEDICINES
MEDICINES
SIDE EFFECTS
Codeine
May cause addiction over a long period of time
Antibiotics Headache, allergic reaction and diarrhea
TYPES OF MEDICINES
MEDICINES
SIDE EFFECTS
Psychothera-peutic medicine
High dose may cause depression, coma, death ,rapid heartbeat and dizziness
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