CHEMICAL FOR CONSUMERS

2014

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 waterii. 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

animalplant

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

ANTIOXIDANTSSTABILIZERS & 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

END