Chemicals for Consumers : Video Playlist

↶ SPM Kimia

5.3 Medicines

Traditional medicine
■ Type of traditional medicines

	►	Obtained from animals, plants and minerals without chemically processed.
	►	The effectiveness depends on belief and experiences.
	►	The knowledges are just passed from one generation to the next generation.

■ Example of traditional medicine

►

Source of traditional medicine Treatment method and uses Aloe vera Using its leaves to treat skin wounds and diseases Garlic Contains antibiotic properties that can treat high blood pressure, prevent cold and asthma. Ginger Using its leaves and rhizomes to prevent cold and remove stomach wind. Ginseng Using its root to make drinks so as to strengthen the body Mint Using its leaves to cure sore throats. Pegaga Using its leaves to treat depression and for longevity.

■ This video contains information regarding traditional medicine.

Types of modern medicine and their uses
■ Modern medicine

	►	A substance that is chemically produced
	►	Can be provided in various forms such as pills, capsules, paste, suspension and solution
	►	Can be divided into : ○ Analgesics ○ Antibiotics ○ Psychotherapeutic drugs

■ This video contains information regarding analgesics.

Modern medicine-analgesics
■ Analgesics

	►	Used to relieve pain.
	►	Types of analgesics: ○ opiates that used to relieve internal pain. ○ non-opiates that used to relieve muscular and skeletal pains.

■ Example of analgesics:

	►	Aspirin To treat fever, relief pain such as headache, toothache and arthritic pain, to reduce inflammation and to reduce the ability of blood to clot. Not suitable for pregnant mothers and children who have flu .
	►	Paracetamol To relieve mild to moderate pain such as headache, muscle and joint pains, period pain and fever. It is not a very effective anti-inflammatory agent. Can be given to children as it does not irritate the stomach.
	►	Codeine It is a stronger analgesic used in headache tablets and cough medicines. It may cause drowsiness after taken. Can be extracted from opium or synthesised from morphine.

■ Preparation of aspirin

►

Can be prepared by adding salicylic acid into ethanoic anhydride.

■ The video below shows the white crystals of aspirin are formed from the reaction between salicylic acid and ethanoic anhydride.

Modern medicine-antibiotic
■ Antibiotic

	►	Used to kill or prevent the growth of bacteria.
	►	Obtained from living organisms such as fungi and bacteria.

■ Example of antibiotic :

	►	Penicillin Extracted from fungus Penicillium notatum A powerful antibiotic used to treat diseases caused by bacterial infections : ○ gonorrhea ○ syphilis ○ syphilis ○ pneumonia ○ meningitis
	►	Streptomycin Produced by soil bacteria of the genus Streptomyces Used to treat : ○ tuberculosis ○ urinary infection ○ TB ○ pneumonia

■ This video contains information regarding antibiotic.

Modern medicine-psychotherapeutic drugs
■ Psychotherapeutic drugs

	►	Used to treat some psychiatric and neurological problems
	►	Psychotherapeutic drugs are classified into: ○ Stimulants ○ Antidepressant ○ Antipsychotic

■ Stimulants

	►	Stimulates the central nervous system.
	►	Speed up metabolic rate to make a person more active.
	►	Increase pulse rate and blood pressure.
	►	High doses or excessive use may cause sleeplessness, anxiety, hallucination or severe depression.

■ Example of stimulants:

	►	Amphetamine A strong and powerful synthetic stimulant that stimulates the central nervous system (nerves and brain). Symptoms of an amphetamine overdose include restlessness, tremor, rapid breathing, confusion, hallucinations.
	►	Cocaine It is applied to certain areas of the body (for example, the nose, mouth, or throat) to cause loss of feeling or numbness. May cause mental and physical problems.

■ Antidepressants

	►	Used to reduce depression in depressed patients
	►	Used to treat a psychotic diseases such as anxiety disorders, eating disorders, chronic pain and abnormal thoughts on killing himself.

■ Example of antidepressant drugs:

	►	Barbiturates It is used to sedate, calm or relax an individual. It is used in sleeping pills to cure people who suffer insomnia. Over dosage may cause death.
	►	Tranquiliser Used to calm a person reduce tension, anxiety and fear.

■ Antipsychotics

	►	Used to treat psychiatric illness such as schizophrenia and mood disorder
	►	Used to treat a patient that not aware of reality, auditory hallucinations (schizophrenia), or become angry easily.
	►	Common antipsychotic medicines are chlorpromazine, reserpine, butyrophenones and clozapine.

■ This video contains information regarding psychotherapeutic drugs

Modern medicine-other medicine
■ Hormones and steroids

	►	Crucial substances for the proper function of the body.
	►	Produced and secreted into the bloodstream by endocrine glands in the body.

■ Example:

	►	Insulin A hormone produced from cells of the pancreas Regulates the amount of sugar in the blood Lack of insulin in the blood can cause diabetes mellitus
	►	Cortisone A steroid hormone released by the adrenal gland in response to stress. Used to treat a variety of skin problems, asthma and arthritis.

■ This video contains information regarding other categories of modern medicine.

The side effects of medicine
■ Side Effects of Medicine

	►	Patient should seek medical advice from a doctor to avoid any side effects
	►	The table below shows the side effects of some medicines Medicine Side effects Aspirin Can cause bleeding and ulcers in the stomach and intestinal wall Can cause unconsciousness Antipsychotic drug May cause addiction Can cause headache, confusion and a high rate of heart beat Amphetamine May cause addiction Can cause aggressiveness and hallucination May develop sleeplessness Barbiturate May cause addiction Can cause death if overdose Penicillin Can cause allergic reactions May cause coma

■ This video contains information regarding the side effects of medicine.

⇲ For exercise(objective and subjective), download for free on Android OS.

5.2 Food Additives

Types of food additives
■ Purpose of food additive

	►	Add flavour
	►	Preserve the food
	►	Improve the food texture
	►	Supply nutrients
	►	Enhance the colour and appearance

■ Types of food additives

	►	Preservatives
	►	Antioxidants
	►	Flavourings
	►	Stabilizers
	►	Thickeners
	►	Colourings

■ This video contains some basic information about food additives.

Preservative
■ Preservative

	►	Added to food to inhibit the growth of bacteria, molds and other microorganisms.
	►	Can increase or extend the self life of food.
	►	Examples of food preservative: Table salt Used to preserve fish and bacon Sugar Used to preserve jelly, fruit jams and fruits Vinegar Used to preserve cut fruits, vegetable and chilli Benzoic acid (C6H5COOH) Used in jams, beer, preserved fruit, pickles, fruit juice, desert sauces and syrups Sodium benzoate (C6H5COONa) Used to preserve fruit juice, chilli sauce and tomato sauce Calcium propuinate ((C2H5COO)2Ca) Used to preserve bread and other baked goods Sodium nitrite (NaNO2) Used to preserve frozen meat, tinner meat, sausages and burgers

■ This video contains information regarding food preservatives.

Antioxidant
■ Food oxidation

	►	When kept for a long time, tends to be oxidised or deteriorate.
	►	Oxidation of oil in food cause the food characteristic change: ○ Becoming rancid. ○ Changing the taste and color. ○ May be toxic.
	►	Processes food that contains antioxidants : cakes, biscuits, margarine, deep fried food and vegetable oil.

■ This video shows why do apples turn brown when exposed to air.

■ Antioxidants

	►	Added to prevent deterioration of fats and oils.
	►	Prevent fats and oils from oxidation that cause rancid fats.
	►	Vegetable oils contain natural antioxidants.
	►	Antioxidant types: ○ Ascorbic acid - Helps to prevent cut and pulped foods from going brown by preventing oxidation reactions that cause the discolouration. ○ Citric acid - Helps to increase the anti-oxidant effects of other substances. ○ Butylated hydroxyanisole (BHA) - Helps to prevent the reactions that break down fats and cause the food to go rancid .
	►	Vitamin C also an antioxidant for fresh fruits and frozen fish.

■ This video contains information regarding antioxidants in food.

Flavouring agents
■ Flavouring

►

Functions to: ○ improve the taste of food. ○ restore taste loss during food processing.

■ Example of most common food flavouring agents

	►	Monosodium Glutamate (MSG) ○ A salt of glutamic acid. ○ No flavour of its own, but it bring out the flavour in meat and fish. ○ Produced from wheat, corn, soybeans or rice.
	►	Aspartame ○ Artificial sweetener (200 times as sweet as natural sugar). ○ A non-carbohydrate sweetener with no caloric value. ○ Suitable for diebetic patient and people who want to lose weight ○ Not suitable for cooking food.
	►	Asesulfame-K ○ Artificial sweetener used in soft drinks, yogurt and desserts. ○ Can be used at higher temperature.

■ This video contains information regarding antioxidants in food.

Stabilisers and thickeners
■ Stabilisers

	►	Functions to: ○ make food taste smoother and finer. ○ help oil and water in food mixed well ○ make food remained in emulsify at all times
	►	Example : ○ acacia gum – used in chewing gum, jelly ○ lecithin - in egg yolk and soy beans
	►	Often added to food such as : Ice-cream Salad dressing Milk Creamy soup

Stabilisers and thickeners
■ Stabilisers

	►	Added to alter the texture of food so that the food become thicker
	►	Example of thickening agents thickeners : ○ pectin – used in jam ○ gelatin – used in yogurt

■ This video contains information regarding stabilisers and thickeners in food.

Food colouring
■ Colouring

	►	Added to enhance the visual appearance of food
	►	Made from natural and artificial food dyes
	►	Colouring ingredients : ○ vegetables dyes ○ inorganic pigments ○ combinations of organic and metallic compounds
	►	Azo compounds are synthetic dyes ○ Red, orange or yellow colours ○ Tartrazine which is orange colour added to orange drinks, apricot jam
	►	Triphenyl compounds ○ Green, blue or purple colours ○ Brilliant Blue (FCF) to give colour to sweets
	►	Other types of dye used : ○ Curcumin - Orange-yellow colour that is extracted from the roots of the turmeric plant. ○ Beta-carotene - Orange-yellow colour found in plants such as carrots, tomatoes and oranges.

■ This video contains information regarding food colouring.

The effect of food additives on health and environment
■ Food additives on health

	►	Excessive intake of food preservatives may cause potential damage to health
	►	Natural or vegetables additives are generally safe
	►	Artificial and synthetic additives have toxic effect
	►	All food additives in Malaysia should follow the Food Act of 1983

■ Effects of food additives on health

►

Food additives Harmful effects if taken in excess Tartrazine Asthma Hyperactive children Sodium nitrite Cancer Monosodium glutamate Have side effects : ○ difficulties in breathing ○ headaches ○ dizziness ○ vomiting Sodium benzoate Can cause allergic reactions to our bodies Can affect the smooth function of our nerves Colouring substances Cancer Migraine Allergy Deformed babies

■ This video contains information regarding effects of consuming food with excess food additivess.

⇲ For exercise(objective and subjective), download for free on Android OS.

5.1.1 - Laboratory Activity : Preparation of Soap by Saponification

Laboratory Activity 5.1.1: Preparation of Soap by Saponification

Aim: To prepare soap through the saponification process.
Problem statement: How is soap prepared in the laboratory?
Hypothesis: The vegetable oil will react with the alkali to form soap during saponification process.
Variable:

	»	Fixed variable : Quantity of sodium hydroxide and vegetable oil
	»	Manipulated variable : Type of vegetable oil
	»	Responding variable : Types of ions discharged at the anode and the cathode

Material: » Sodium hydroxide 5mol dm-3 » Sodium Chloride » Corn oil » Soy oil » Palm oil » Olive oil

Apparatus: » Beaker » Glass rod » Measuring cylinder » Tripod stand » Wire gauze » Spatula » Bunsen burner

Procedure:

►

1. The animation below shows the arrangement of the apparatus and the observation of the experiment. 2. 5cm3 of palm oil are measured by measuring cylinder and poured into a beaker. 3. 30cm3 of sodium hydroxide are measured and added into the beaker. 4. The mixture is stirred constantly and heated until boiling for about 10 minutes. 5. 50cm3 of water and one spatula of sodium chloride are added into the beaker. 6. The mixture is boiled for another 5 minutes and then cool down to room temperature. 7. Product formed are filtered and dried with pieces of filter paper. 8. The residue is then touched using fingers. 9. The residue is then mixed and stirred together with water 10. The experiment is repeated with different vegetable oil.

Observation:

►

Dilute sulphuric acid Vegetable oil Product formed Smoothness Test with water Palm oil White semi solid Smooth Many bubbles are produced Corn oil White semi solid Smooth Many bubbles are produced Soy oil White semi solid Smooth Many bubbles are produced Olive oil White semi solid Smooth Many bubbles are produced

Analysis:

	►	The white semi-solid is called soap as it will form bubbles with with water.
	►	The chemical equations for the formation of soap are shown below: ○ Palm oil + alkali → sodium salt of fatty acid + glycerol ○ Corn oil + alkali → sodium salt of fatty acid + glycerol ○ Soy oil + alkali → sodium salt of fatty acid + glycerol ○ Olive oil + alkali → sodium salt of fatty acid + glycerol

Discussion:

	►	The presence of sodium chloride helps the soap to precipitate. Sodium chloride makes the soap less soluble by helping the solid soap to form from the liquid soap solution.
	►	The flame should be controlled during the boiling process to avoid bubbling of mixture.

Conclusion:

►

The boiling of different vegetables oil with concentrated alkaline solution will procedure soap.

⇲ For exercise(objective and subjective), download for free on Android OS.

5.1 Soaps and Detergents

Soaps
■ Soaps

	►	Mostly are water-soluble substances.
	►	Either sodium salts or potassium salts of long-chain fatty acids.
	►	General formula: ○ RCOONa for sodium soap ○ RCOOK for potassium soap R stands for alkyl groups of carbon chain (Each alkyl group have a hydrocarbon chain containing 12 to 18 carbon atoms)
	►	Example: Examples of soap Formula Sodium laurate CH3(CH2)10COO−Na+ Potassium oleoate CH3(CH2)7CH=CH(CH2)7COO−K+ Sodium palmitate CH3(CH2)14COO−Na+ Sodium stearate CH3(CH2)16COO−Na+

■ The history of soap manufacturing

	►	In ancient time, soap was made by mixing vegetables with ashes of plants that contain potassium carbonate.
	►	In 1791, Nicholas Le Blanc (1742-1806) – discovered a way to produce from sodium hydroxide.

Preparation of Soaps
■ Saponification

	►	The process that is used for making soap.
	►	Involves the hydrolysis process between ester (oil or fat) and concentrated alkali solution ○ concentrated alkaline solution acts as a catalyst ○ Fat (from animals) or oil (vegetable oil) is hydrolysed
	►	Big ester molecules are break down to fatty acids and glycerol. ○ fat + alkali → fatty acid salt (soap) + glycerol

■ During the saponification process:

	►	Animal fat or vegetables fat is heated with sodium hydroxide.
	►	Once the saponification reaction is complete, sodium chloride is added to precipitate the soap.
	►	Sodium chloride is added to reduce the solubility of soap in water and causes the solid soap form from the liquid soap solution.
	►	The soap can be separated from the solution by filtration.

■ Additives added to soap

	►	Colouring and perfumes.
	►	Optical brighteners as whitening agent.
	►	Water softeners that used in areas with hard water.
	►	Abrasives that increase the power of cleansing action.

■ The video below shows the preparation of making soap.

■ The video below shows the preparation of making soap.

Laboratory Activity 5.1.1 : Preparation of Soap by Saponification

Cleansing action of Soaps
■ Structure of soap molecules

►

Each soap molecule consists of two parts : ○ Ionic head (hydrophilic) (−COO−Na+) which are soluble in water. ○ Long hydrocarbon chain as the tail (hydrophobic) which are soluble in grease or oil.

■ Functions of soap:

	►	Wetting agent – reduce the surface tension of water to allow water spread out and wet the surface of the material.
	►	Emulsifying agent - capable of dispersing one liquid into another immiscible liquid. This means that while oil (which attracts dirt) doesn't naturally mix with water, soap can suspend oil/dirt in such a way that it can be removed.

■ Cleansing action of soap

	►	The animation below shows the cleansing action of soap.
	►	The head region (hydrophilic part) attracts water molecules and the dissolve in water. ○ Soap reduces the surface tension of the water. ○ Spreads out the water and then wet the clothes.
	►	The tail region (hydrophobic end) will attract grease and mix with the particles of grease. ○ Grease begins to be lifted off the surface on agitation.
	►	The soap chains surround the grease particles. ○ Attraction of the head end of soap molecule to water. ○ Washing motion of the clothes pull off the soap and grease. ○ Grease dirt are removed from clothes surface as emulsion (oil droplets).
	►	The particles of dirt and grease come off the surface and remain suspended in the water when the water is stirred or agitated. ○ Soap can hold the suspended particles because it can lather (bubbles) with water
	►	Removing dirty water and soap foam will remove grease dirt as well.

■ The video below shows how does a soap work.

Detergent
■ Detergent

	►	Salt that is produced from the reaction between an alkali and a sulphonic acid.
	►	Non-soap cleaning chemicals that made from petroleum fractions.
	►	Having the similar molecular structure of soap.

■ Sodium salt of sulphonic acid

	►	Sodium alkyl sulphate ○ Example: Sodium lauryl sulphate CH3(CH2)11–SO3−Na+
	►	Sodium alkyl benzene sulphonate ○ Example: Sodium n-dodecylbenzene sulphonate CH3(CH2)11–C6H4–SO3−Na+

■ Preparation of detergent sodium lauryl sulphate(Sodium alkyl sulphate)

	►	Sulphonation ○ ○ The long chain alcohol reacts with concentrated sulphuric acid ○ Water and alkyl sulphonic acid are formed
	►	Neutralisation ○ ○ Alkyl sulphonic acid is neutralised by adding sodium hydroxide. ○ Sodium alkyl sulphate (detergent) is formed.

■ Preparation of Detergent Sodium Alkylbenzene Sulphonate

	►	Alkylation ○ ○ Alkene carbon chain from petroleum react with benzene. ○ Alkylbenzene is formed.
	►	Sulphonation ○ ○ Alkylbenzene is reacted with concentrated sulphuric acid. ○ Alkylbenzene sulphonic acid is formed.
	►	Neutralisation ○ ○ Sodium hydroxide is added to neutralise alkylbenzene sulphonic acid. ○ Sodium alkylbenzene sulphonate(detergent) is formed.

■ This video contains information regarding detergents.

Cleansing action of detergent
■ Structure of detergent

	►	Detergent ionise in water to form detergent ions and sodium ions
	►	Detergent ions consist of hydrophilic head(ionic part) and hydrophobic tails (hydrocarbon chain). alkyl sulphate ions alkylbenzene sulphonate ions
	►	The structure of detergent is similar to that of soap.

■ Cleansing action of detergent

	►	The cleansing action of detergent is similar to that of soap.
	►	The tail region (hydrophobic tails) is soluble in grease but not in water.
	►	The head region (hydrophilic head) is soluble in water but not in grease.
	►	During the washing action, all the tails molecules will go into the grease and the head dissolve in water. When the water is shaken, all detergents molecules will remove the grease (dirt) away.

■ The video below shows how does a detergent work.

Effectiveness of the cleansing action of soap and detergent
■ Soap cannot be used in hard water

►

Soap effectiveness is reduced when used in hard water.

■ Hard water

►

The water that contains dissolved calcium and magnesium salts.

■ Soap in hard water

	►	Soap form scum (non-soluble precipitate) with hard water
	►	Calcium and magnesium ions in hard water will react with soap anions to form scum as shown in the following equations: ○ RCOO−(aq) + Ca2+(aq) → (RCOO)2Ca(s) ○ RCOO−(aq) + Mg2+(aq) → (RCOO)2Mg(s)
	►	The soap will have to react with all the calcium and magnesium ions before it start cleaning actions.
	►	The scum that are formed will leave a clear sediment that can be seen on clothes.

■ Detergents can be used in hard water

	►	Detergents are similar to soap, but they are less likely to form soap scum. ○ 2ROSO−Na+(aq) + Mg2+(aq) → (ROSO)2Mg(aq) + 2Na+(aq) ○ 2ROSO−Na+(aq) + Ca2+(aq) → (ROSO)2Ca(aq) + 2Na+(aq)
	►	Detergents are not affected by the presence of minerals in water (hard water), so cleaning action in hard water can be improved by using detergent.

Additives in detergent
■ Detergent additives

	►	give certain characteristics.
	►	provide extra useful for commercial purpose.
	►	increase the washing power.

■ The additives

►

The table below shows the additives with their functions Additive Functions Whitening agent (Sodium perborate) Remove colored dirt stains on white clothes Florescence agent Makes white clothes look whiter and more sparkling Biological enzymes Remove protein stains Phosphate compound (Sodium triphosphate) Helps displace mud from clothes Softens the water Drying agent (Sodium sulphate and sodium silicate) Make sure the detergent powder in dry condition. Stabiliser (Alkyl monoethanolamide) Reduce the amount of bubbles formed Anticoagulant Prevents the washed-out dirt from sticking back to the clothes Perfume Give fragrances to clothes after cleaning Make the washed clothes smell fresh and clean

Comparison between soap and detergent
■ Similarities between soap and detergent

	►	Both are cleansing agents which act as emulsifying agent and wetting agent
	►	Both molecules consist of hydrophilic head (ionic part) and hydrophobic tails (hydrocarbon chain).

■ Soap differs from detergent in some aspects:

►

Differences Soap Detergents Made from Natural materials found in animals and plants Synthetic materials from petroleum Formation Reaction between an alkali and a fatty acid Reaction between an alkali and a sulphuric acid Effectiveness in hard water No effective in hard water due to formation of scum. Effective in hard water. Do not form scum in hard water Environment impact Easily broken down by bacteria or biodegradable Not easily broken down by bacteria or not biodegradable. May cause pollution

■ The video below shows the comparison between soap and detergent.

⇲ For exercise(objective and subjective), download for free on Android OS.