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TOPIK 1 :
BANDING BEZA BAHAN ASLI DAN BAHAN BUATAN MANUSIA
BAHAN ASLI BAHAN BUATAN
tulen dan semula jadi
mudah diurai dan degradasikan
berasal daripada tumbuh-tumbuhan,
haiwan atau tanah
Reka bentuk untuk
Tidak mengurai dan
Ia biasanya dibuat
daripada beberapa bahan
Boleh diwujudkan oleh
proses fizikal dan kimia
Petroleum (Bahan Api)
Bahan-bahan bukan organik (batu)
Rencam (tanah liat, porselin)
bahan kimia industri,
Kayu (rotan, buluh, kulit kayu)
Logam (tembaga, gangsa, besi, emas,
Gentian Semula jadi (benang bulu,
sutera, kapas, flaks, hem, jut, kapok)
TOPIK 2 : FEUL
Fuel is any material that can be used to generate energy to produce mechanical
work in a controlled manner. The processes used to convert fuel into energy
include chemical reactions, such as combustion, and nuclear reactions, such
as nuclear fission or nuclear fusion. Fuels are also used in the cells of organisms in a
process known as metabolism. Hydrocarbons are by far the most common source of
fuel in current use, but many other substances can be used as well.
Fossil fuels are hydrocarbons, primarily coal and petroleum (liquid
petroleum or natural gas), formed from the fossilized remains of dead plants and
animals by exposure to heat and pressure in the Earth's crust over hundreds of
millions of years. In common parlance, the term fossil fuel also includes
hydrocarbon-containing natural resources that are not derived entirely from biological
sources, such as tar sands. These latter sources are properly known as mineral
Fossil fuels release millions of greenhouse gases into the air, but they do have some
Fuel for our automobiles
Energy for heating and cooling
There are many disadvantages of using fossil fuels:
Produce greenhouse gases
Non-renewable energy source
Contribute to global warming
Deplete the ozone
Aid in acid rain
A mixture of a wide range of molecules which is pumped or mined from underground
reservoirs. As a mixture it has very little value; too runny for paving, too thick for an
engine. Fortunately each molecule boils at a different temperature, which is the basis
of distillation.Fractional distillation of crude oil is the first step in the production of
many of the materials we have come to rely on in modern life.
Petroleum is a mixture of hydrocarbon molecules. The molecules have different
sizes and numbers of carbon atoms. The small molecules have few carbon atoms
and low boiling points, while the large molecules have many carbon atoms and high
boiling points. In this form, petroleum is difficult to ignite and therefore is of little use.
It must be refined to make useful fuels and chemicals.
Petroleum is used for:
Fraction of crude oils and its uses
Refinery Gas 3 or 4 below 30Bottled Gas
(propane or butane).
Petrol 7 to 9 100 to 150Fuel for car
Naphtha 6 to 11 70 to 200Solvents
and used in petrol.
(paraffin)11 to 18 200 to 300
Fuel for aircraft
Diesel Oil 11 to 18 200 to 300
Fuel for road
Lubricating Oil 18 to 25 300 to 400Lubricant for engines
Fuel Oil 20 to 27 350 to 450Fuel for ships
Greases and Wax 25 to 30 400 to 500Lubricants
Bitumen above 35 above 500Road surface
An ore is a type of rock that contains minerals with important elements
including metals. The ores are extracted through mining; these are then refined to
extract the valuable element(s).
The grade or concentration of an ore mineral, or metal, as well as its form of
occurrence, will directly affect the costs associated with mining the ore. The ores
must be processed to extract the metals of interest from the waste rock and from the
ore minerals. Ore bodies are formed by a variety of geological processes. The
process of ore formation is called ore genesis.
A mineral is composed of the same substance throughout. If you were to cut a
mineral sample, it would look the same throughout. There are about 3000 different
minerals in the world. Minerals are made of chemicals - either a single chemical or a
combination of chemicals.
PROPERTIES OF MINERALS
Characteristics used in the identification & study of minerals. These
are the most common characteristics used when describing minerals.
Color – this varies depending on the chemicals present
and is the least informative in identifying a mineral
Luster – what the surface looks like in the light
Specific Gravity – how heavy it feels, heft
Crystal Form – shape of crystal, shape the mineral
would take if it had room to grow in a cavity,
not massive – some minerals have a number of
different crystal shapes
Cleavage – pattern when mineral is broken – in planes
Tenacity - toughness, how cohesive the mineral is, if it
Hardness – what it can scratch & what scratches it
Transparency - The ability to transmit light. Depending
on a number of things,
rocks & minerals can also transmit light.
Many rocks that are opaque when in a chunk, are
translucent when cut into very thin slices.
Gems stones are often valued on how clear, or
transparent they are.
Special Properties– magnetism, chatoyancy,
fluorescence, odor, streak, burn test, conductivity
alloy is as a material that's made up of at least two different chemical elements,
one of which is a metal. An alloy is a combination, either in solution or compound, of
two or more elements, at least one of which is a metal, and where the resultant
material has metallic properties.
Alloys are often used to enhance properties of a metal. Metallic elements are
blended with other metals or non-metallic substances to give them special qualities,
such as corrosion resistance, greater hardness or more strength. Alloys are made by
melting the main metals and then dissolving the other substances in it.
Alloy Components Typical uses
Iron (50%+), aluminium (8-
12%), nickel (15-25%), cobalt (5-
40%), plus other metals such as
copper and titanium.
in loudspeakers and
pickups in electric guitars.
AmalgamMercury (45-55%), plus silver, tin,
copper, and zinc.Dental fillings.
Tin (90%), antimony (7-15%), copper
in machine bearings.
Brass Copper (65-90%), zinc (10-35%). Door locks and bolts,
Copper (78-95%), tin (5-22%), plus
manganese, phosphorus, aluminium,
Cast ironIron (96-98%), carbon (2-4%), plus
Metal structures such
as bridge sand heavy-duty
Copper (75%), nickel (25%), plus
small amounts of manganese.Coins.
Aluminium (94%), copper (4.5-5%),
magnesium (0.5-1.5%), manganese
Automobile and aircraft
body parts, military
GunmetalCopper (80-90%), tin (3-10%), zinc
(2-3%), and phosphorus.Guns, decorative items.
Magnox Magnesium, aluminium. Nuclear reactors.
Nichrome Nickel (80%), chromium (20%).
elements in electrical
Nitinol Nickel (50-55%), titanium (45-50%). Shape memory alloy used
in medical items, spectacle
frames that spring back to
shape, and temperature
PewterTin (80-99%) with copper, lead, and
Ornaments, used to make
before glass became more
Varies. Old-fashioned solders contain
a mixture of tin (50-70%), lead (30-
50%), copper, antimony, and other
metals. Newer solders dispense with
lead for health reasons. A typical
modern solder has 99.25 percent tin
and 0.75 percent copper.
components into circuits.
Iron (80-98%), carbon (0.2-2%), plus
other metals such as chromium,
manganese, and vanadium.
Metal structures, car and
airplane parts, and many
Iron (50%+), chromium (10-30%),
plus smaller amounts of carbon,
nickel, manganese, molybdenum,
and other metals.
Jewellery, medical tools,
StelliteCobalt (67%), chromium (28%),
tungsten (4%), nickel (1%).
cutting tools such as saw
teeth, lathes, and
silverSilver (92.5%), copper (7.5%).
Cutlery, jewelry, medical
tools, musical instruments.
Gold (75%), palladium (17%), silver
(4%), copper (4%)Jewelry.
Bismuth (50%), lead (26.7%), tin
(13.3%), cadmium (10%).
Solder, melting element
in fire sprinkler systems.
Aromatic hydrocarbons are a class of chemical substances which are characterized
by having molecular structures which are called benzene rings. The chemically
simplest aromatic hydrocarbon is benzene, and the structure of this hydrocarbon lent
its name to the benzene ring. Many aromatic hydrocarbons are toxic, and they are
unfortunately among the most widespread of organic pollutants.
Nuclear Substituted Compounds
When the functional group or any substituent, in aromatic compounds is directly
attached to the benzene ring, it is a called nuclear substituted compound. Such
compounds are named as the derivatives of benzene under the IUPAC system.
However, the common names of many such compounds are retained by IUPAC.
Sidechain Substituted Compounds
Aromatic compounds where the functional group is present in the sidechain of the
ring are called sidechain substituted compounds. Sidechain substituted compounds
are named as the phenyl derivatives of the corresponding aliphatic compounds.
Physical Properties of Aromatic Hydrocarbons
The melting and boiling points of aromatic hydrocarbons increase with the molar
mass, and are higher than that of the corresponding aliphatic hydrocarbons.
They are soluble in organic solvents,
Insoluble in water, and
Lower densities than water.
As an industrial solvent for fats and oils, rubber, resins etc.
As a starting material for dyes, drugs, perfumes and explosives and polymers
For dry-cleaning of woollen clothes.
The manufacture of ethanol from ethene
Ethanol is manufactured by reacting ethene with steam. The catalyst used is solid
silicon dioxide coated with phosphoric(V) acid. The reaction is reversible.
Only 5% of the ethene is converted into ethanol at each pass through the reactor. By
removing the ethanol from the equilibrium mixture and recycling the ethene, it is
possible to achieve an overall 95% conversion.
Uses of ethanol
The "alcohol" in alcoholic drinks is simply ethanol.
Industrial methylated spirits (meths)
Ethanol is usually sold as industrial methylated spirits which is ethanol with a small
quantity of methanol added and possibly some colour. Methanol is poisonous, and
so the industrial methylated spirits is unfit to drink. This avoids the high taxes which
are levied on alcoholic drinks (certainly in the UK!).
As a fuel
Ethanol burns to give carbon dioxide and water and can be used as a fuel in its own
right, or in mixtures with petrol (gasoline). "Gasohol" is a petrol / ethanol mixture
containing about 10 - 20% ethanol.
Because ethanol can be produced by fermentation, this is a useful way for countries
without an oil industry to reduce imports of petrol.
As a solvent
Ethanol is widely used as a solvent. It is relatively safe, and can be used to dissolve
many organic compounds which are insoluble in water. It is used, for example, in
many perfumes and cosmetics.
Uses of methanol
As a fuel
Methanol again burns to form carbon dioxide and water.
It can be used a a petrol additive to improve combustion, or work is currently being
done on its use as a fuel in its own right.
As an industrial feedstock
Most methanol is used to make other things - for example, methanal (formaldehyde),
ethanoic acid, and methyl esters of various acids. In most cases, these are in turn
converted into further products.
Ether is the general name for a class of chemical compounds which contain an ether
group — an oxygen atom connected to two (substituted) alkyl groups. A typical
example is the solvent and anesthetic diethyl ether (ethoxyethane, CH3-CH2-O-CH2-
• An ether has two organic groups (alkyl, aryl, or vinyl) bonded to the same
oxygen atom, R–O–R¢
• Formula R-O-R where R is alkyl or aryl.
• Symmetrical or unsymmetrical
Ether molecules cannot form hydrogen bonds among each other, resulting in
a relatively low boiling point comparable to that of the analogous alkanes.
Ethers are more hydrophobic than esters or amides of comparable structure
Ethers are hydrogen bond acceptors- they are more soluble in H2O than are
Uses of ether:
The following are the general uses of ether,
Diethyl ether is used in anaesthia.
In Grignard reaction,it is used as a solvent.
Used as a solvent for resins, oils, fats, and gums.
Used for refrigerator purposes.
Preaparation of Aldehydes and Ketones
Oxidising alcohols to make aldehydes and ketones
The oxidising agent used in these reactions is normally a solution of sodium
or potassium dichromate(VI) acidified with dilute sulphuric acid.
If oxidation occurs, the orange solution containing the dichromate(VI) ions is
reduced to a green solution containing chromium(III) ions.
The net effect is that an oxygen atom from the oxidising agent removes a
hydrogen from the -OH group of the alcohol and one from the carbon to which
it is attached.
[O] is often used to represent oxygen coming from an oxidising agent.
R and R' are alkyl groups or hydrogen. They could also be groups containing
a benzene ring, but I'm ignoring these to keep things simple.
If at least one of these groups is a hydrogen atom, then you will get an
aldehyde. If they are both alkyl groups then you get a ketone.
If you now think about where they are coming from, you will get an aldehyde if
your starting molecule looks like this:
In other words, if you start from a primary alcohol, you will get an aldehyde.
Uses of aldehydes and Ketone
1. manufacture of resins, dyes, and organic acids.
2. Formaldehyde can be used to preserve dead animals. Formaldehyde is well
recognized as formalin solution used to defend biological specimens and to
prepare Bakelite, urea-formaldehyde glues and other polymeric products.
3. Benzaldehyde is an almond extract. Benzaldehyde is used in perfumery with in
4. Acetone is a common fingernail polish remover and is a solvent. Acetone is very
flammable. Acetone with ethyl methyl ketones are general industrial solvents.
5. 2-Butanone (MEK, methyl ethyl ketone) is used as a solvent and paint stripper. 2-
Butanone is very flammable.
6. (-)-Carvone is used as spearmint flavoring.
7. (+)-Carvone is used as caraway seed flavoring. Vanillin is the vanilla flavoring.
8. Aldehydes and ketones are used as solvents, starting materials and reagents for
the sysnthesis of other products.
9. Aldehyde is used primarily as an initial material in the manufacture of acetic acid,
ethyl acetic, vinyl acetate, polymers and drugs.
10.Various aldehydes and ketones exemplar, butyraldehyde, vanillin,
acetophenone, camphor, etc. are well recognized in support of their odours and
Uses of Carboxylic Acids:
They are used in several food produce and pharmaceuticals to include flavors. Some
of these families are manufactured for apply as solvents that are acetone and for
prepare materials similar to adhesives, paints, resins, perfumes, plastics, fabrics, etc
Methanoic acid: use as rubber, textile, dyeing, leather and electroplating
Ethanoic acid: use as solvent and as vinegar in food industry.
Hexanedioic acid: manufacture of nylon 6:6.
Ester of benzoic acid: use as perfumery.
Sodium benzoate: use as a food preservative.
Higher fatty acids: use as manufacture of soaps and detergents
Esters are derivatives of the carboxylic acids in which the -OH part of the carboxylic
group has been replaced by -OR group where R may be alkyl or aryl group.
A carboxylic acid contains the -COOH group, and in an ester the hydrogen in this
group is replaced by a hydrocarbon group of some kind. This could be an alkyl group
like methyl or ethyl, or one containing a benzene ring like phenyl.
Esters are compounds formed from the reaction between alcohols and acids. The
word 'ester' alone now signifies by common usage that the acid is an organic acid,
but inorganic acids can also form esters
Uses of Esters
Esters are used as softeners in molding and plastic industries, in artificial fragrances
or scents, as solvents in pharmaceutical industries, as industrial solvents for making
fats, cellulose, paints and varnishes, and used in making artificial food flavors that
are added into food such as ice cream and sweets.
Esters are used in making various products like plastics, polymers, explosives.
They are also used as solvent for oils, fats, cellulose resins etc..,
They are also used in making artificial flavours and essences.
Esters are also being successively used as the alternative to diesel.
The salicylic methylester has amazing fragrance, the formula is given below.
Acid amides may be regarded as the derivatives of carboxylic acids in which -OH
part of the carboxylic group is replaced by the -NH2 group.
Acid anhydrides are considered to be derived from carboxylic acids by the removal
of a molecule of water from the two molecules of the acid.
Plastics are synthetic chemicals extracted mainly from petroleum and composed
of hydrocarbons (compounds made from chains of hydrogen and carbon atoms).
Most plastics are polymers, long molecules made up of many repetitions of a basic
molecule called a monomer; in effect, the monomers are like identical railroad cars
coupled together to form a very long train.
Thermoplastic polymers can be heated and formed, then heated and
formed again and again. The shape of the polymer molecules are generally
linear or slightly branched. This means that the molecules can flow under
pressure when heated above their melting point.
Thermoset polymers undergo a chemical change when they are heated,
creating a three-dimensional network. After they are heated and formed,
these molecules cannot be re-heated and re-formed.
Ammonia (NH3) is an important compound of nitrogen and hydrogen, can take the
form of a strong smelling liquid or gas. It is a colourless gas with a choking smell,
and a weak alkali which is very soluble in water.Most popularly, consumer and
commercial products use the alkaline substance to clean grime or fertilize crops.
The Haber process
The raw materials for this process are hydrogen and nitrogen. Hydrogen is obtained
by reacting natural gas - methane - with steam, or through the cracking of oil.
Nitrogen is obtained by burning hydrogen in air. Air is 80 per cent nitrogen; nearly all
the rest is oxygen. When hydrogen is burned in air, the oxygen combines with the
hydrogen, leaving nitrogen behind.
Nitrogen and hydrogen will react together under these conditions:
a high temperature - about 450ºC
a high pressure - about 200 atmospheres (200 times normal pressure)
an iron catalyst
The reaction is reversible.
nitrogen + hydrogen ammonia
N2(g) + 3H2(g) 2NH3(g)
The most important and useful oxoacid of nitrogen is nitric acid. Its molecular formula
is HNO3 and molar mass 53 g mol-1.
The conversion of ammonia into nitric acid in this process is done through the
Oxidation of ammonia to nitric oxide
Ammonia is oxidized by air in the presence of Pt catalyst at 800°C to give nitric
Oxidation of NO to NO2
The nitric oxide is oxidised by air at temperature below 100°C, to give nitrogen
Formation of nitric acid
Nitrogen dioxide is then converted to nitric acid by absorbing NO2 in water, in the
presence of air.
Uses of Nitric acid
The important uses of nitric acid are as follows:
1) Nitric acid plays a significant role in the manufacture of various products such as:
Explosives like trinitrotoluene (T.N.T.) nitro glycerine, gun cotton, ammonal etc.
Fertilizers such as calcium nitrate, ammonium nitrate etc.
Nitrate salts such as calcium nitrate, silver nitrate, ammonium nitrate.
Dyes, perfumes, drugs etc. from coal tar products.
Sulphuric acid by Lead Chamber process.
2) It is used in the purification of silver, gold, platinum etc.
3) Nitric acid is used in etching designs on copper, brass, bronze ware etc
4) It is used to prepare "aqua regia" to dissolve the noble elements.
5) It is used as a laboratory reagent.
Sulphuric acid, H2SO4, is one of the most important industrial chemicals. It is an oily
liquid having a boiling point of 335 ºC, which evolves much heat on dilution with
water. Millions of tons of sulphuric acid are made every year by the CONTACT
PROCESS, which converts raw sulphur, oxygen and water to sulphuric acid.
Step 1: Melted sulphur is burned in a furnace, using air, producing sulphur
Step 2: The SO2 gas is passed through a tower called a precipitator in order to
remove dust and other impurities which might interfere with the catalyst.
Step 3: The SO2 is then washed with water, in a scrubbing tower.
Step 4: The SO2 is then dried in a drying tower.
Step 5: After passing through a heating chamber, the SO2, which is still mixed
with air, is passed through a reactor. There, using vanadium pentoxide, V2O5, as
catalyst, the SO2 is converted to sulphur trioxide, SO3.
Step 6: Finally, the SO3 is absorbed in concentrated sulphuric acid, giving the so-
called oleum or pyrosulphuric acid. This is the diluted with water to give about
98% pure H2SO4.
Uses of sulphuric acids in our daily life
In the manufacture of fertilizers, ammonium phosphate and calcium super
In the manufacture of rayon and nylon and also in the preparation of dyes and
drugs from coal tar derivatives.
In the manufacture of the explosives such as Tri-nitro toluene , Tri-nitro glycerine
and picric acid.
In the manufacture of nitric acid, hydrochloric acid and phosphoric acid.
In the manufacture of sodium sulphate for glass industry and ferrous sulphate for
In the purification of petrol, kerosene, and lubricants.
It is used in metallurgy for extraction of metals. Leaching of metallic compounds
gives sulphates which on electrolysis gives the metal in pure form .It is used for
pickling of metals.
It is used in storage of batteries.
It is used as a laboratory reagent for the preparation of iodine, carbon monoxide
Composites are made by combining two or more natural or artificial materials to
maximize their useful properties and minimize their weaknesses. One of the oldest
and best-known composites, glass-fiber reinforced plastic (GRP or FRP),
combines glass fibers (which are strong but brittle) with plastic (which is flexible) to
make a composite material that is tough but not brittle. Composites are typically used
in place of metals because they are equally strong but much lighter.
Composites exist in nature. A piece of wood is a composite, with long fibres of
cellulose (a very complex form of starch) held together by a much weaker substance
called lignin. Cellulose is also found in cotton and linen, but it is the binding power of
the lignin that makes a piece of timber much stronger than a bundle of cotton fibres.
Types of Composite
Composites can be easily found in nature. Wood is an example of a composite
because cellulose fibers are held together by substance called lignin. These fibers
can be found in cotton and thread, but it's the bonding power of lignin in wood that
makes it much tougher. Another natural composite is rock and sand, materials used
in concrete. Rock is just smaller rocks held together, and sand is made of small
One type of very old composite material invented by early humans was the mud
brick. A normal mud brick is sturdy and resistant to compression, but can break if
bent. Straw is a material that has excellent tensile strength, meaning that it resists
stretching. By combining both, early humans were able to create composite mud
bricks that could resist weight and compression as well as stretching.
Concrete is a composite material made of cement, sand, stones and water.
Combined, concrete is stronger than any one of these materials. Concrete is used
heavily in building and road construction.
Fiberglass is a material made of tiny glass shards held together by resin and other
components. In the automotive industry, fiberglass is important for making body kits.
The body shell for a car is made up of different layers of fiberglass, such as a gel-
coat layer, tissue layer, matting and cloth. The final product is a complete,
waterproof, lightweight and strong body kit. Fiberglass can also be a less expensive
alternative to other materials.
Ceramics once referred purely to pottery and to articles made by firing materials
extracted from Earth. Today, the term has a much broader definition. Ceramics
are generally thought of as inorganic and nonmetallic solids with a range of useful
properties, including very high hardness and strength, extremely high melting
points, and good electrical and thermal insulation.
The best-known ceramics are pottery, glass, brick, porcelain, and cement. But
the general definition of a ceramic—a nonmetallic and inorganic solid—is so
broad that it covers a much wider range of materials.
Main properties of glass
These are the main characteristics of glass:
- Solid and hard material
- Disordered and amorphous structure
- Fragile and easily breakable into sharp pieces
- Transparent to visible light
- Inert and biologically inactive material.
- Glass is 100% recyclable and one of the safest packaging materials due to
its composition and properties
Soaps are sodium or potassium salts of higher fatty acids like stearic, palmitic
and oleic acids. Fatty acids are organic acids that have more than sixteen carbon
atoms in their molecular structure. The sodium soaps are called hard soaps and the
potassium soaps are known as soft soaps. Soaps are obtained from oils and fats.
For e.g., tristearin is got from beef and mutton tallow, tripalmitin from palm oil and
triolein from lard (pig fat), olive oil and cotton seed oil. In India, soap is commonly got
from coconut, groundnut, til and mahua oils.
Manufacture of Soap – Saponification
Saponification is the process where oil or fat (tristearin) is treated with sodium
hydroxide solution called lye, to form soap and glycerine.
Oil or fat is taken in a huge iron-pan called soap kettle and heated with open steam.
10% sodium hydroxide solution (lye) is added in a thin stream. The steam keeps the
mass boiling and ensures thorough mixing as well. Saponification is complete after
several hours to give a frothy mixture of sodium salts and glycerine.
Salting out of Soap
Saponfication is complete when we see a slight excess of the alkali in the
transparent reaction mixture. Common salt or brine is then added to precipitate soap
and heating is continued. Soap forms in the upper layer as a thick mass. This is
known as salting out of soap.
The unused alkali solution in the lower layer is called spent lye or sweet lye. This
along with glycerol and salts is drawn from below the reaction vessel. Glycerol can
be recovered from this.
The soap obtained after salting out is boiled again with sodium hydroxide for
complete saponificaiton. This converts all the unsaponified fat. The spent lye is then
drawn off. The solid soap is then boiled with water to dissolve excess of alkali. It is
then allowed to settle when the impure soap called nigre forms the lower layer. The
pure soap in the upper layer is transferred through a swing pipe to a steam-jacketed
tank called crutcher.
It is then shredded into small chips, dried to the requisite amount of moisture content
and mixed with colouring substances and perfumes. Some fillers like rosin, sodium
silicate, borax and sodium carbonate are added to laundry soaps. They have
detergent value and are less expensive than soap.
In the next step, the soap is allowed to run into moulds and permitted to solidify. The
bigger blocks are then cut with steel wires into smaller slabs, which are then cut into
smaller cakes and stamped.
Synthetic detergents possess the desirable properties of ordinary soaps and
can be used with hard water and in acidic solutions as well. Synthetic detergents are
sodium salts of long chain benzene sulphonic acids or sodium salt of long chain alkyl
hydrogen sulphates. Their calcium or magnesium salts are soluble in water.
The hydrophobic part is the hydrocarbon chain and the water soluble part can be:
An anionic group like sulphate or sulphonate
A cationic group like amine salt or quaternary ammonium compound
A non-ionic group like alcohol or ether
Some of the synthetic detergents with a branched hydrocarbon chain have very
They are resistant to bacterial attack and are not fully degraded in sewage
treatment units. Therefore, they cause water pollution when they are discharged
into a river or any other water body.
Phosphate salts present in synthetic detergents cause rapid growth of algae that
deplete the oxygen content in the water. (A condition known as eutrophication).
Due to this aquatic animals die resulting in the imbalance of the ecosystem as
These detergents lower the surface tension of water and act as cleansing agents
They can be used for delicate fabrics because they do not hydrolyze to give
They have equal action in both hard and soft water
Soaps are sodium salts of higher fatty
Detergents are sodium salts of long chain
benzene sulphonic acid or the sodium salts
of a long chain alkyl hydrogen sulphate
Calcium and magnesium salts of
soaps are in soluble in water.
Therefore cleansing action of soap
reduces in hard water
Calcium and magnesium salts of
detergents are soluble in water. Therefore
cleansing action of detergents remain
unaffected in hard water
Soaps are prepared from natural oils
Synthetic detergents are prepared from
hydrocarbons of petroleum
Soaps cannot be used in acidic
medium Detergents can be used in acidic medium
Soaps are biodegradable Most of the detergents are non-
. Gelang getah dibuat dari getah, yang merupakan sejenis polimer yang dipanggil
elastomer. Sebagai elastomer, gelang getah berbeza daripada bahan-bahan pepejal
yang lain kerana ia boleh diregangkan lebih daripada empat kali ganda panjang
asalnya dan apabila dilepaskan dengan mudah ia akan kembali ke panjang
asal. Sifat ini dikenali sebagai kekenyalan
Getah Asli ialah polimer tambahan isoprena, C5H8. Nama IUPAC bagi isoprena ialah
2-metilbut-1,3-diena. Sebagai contoh, getah asli adalah sangat kenyal dan dibuat
dariapda monomer isoprena.
Pemvulkanan Getah Asli
Pemvulkanan getah asli merupakan satu proses perangkaian silang yang ditemui
oleh Charles Goodyear pada tahun 1839. Goodyear secara tidak sengaja
mendapati bahawa menambah sulfur kepada getah asli diikuti dengan
pemanasan campuran menjadikan getah lebih kuat dan lebih tahan terhadap
pengoksidaan atau tindak balas yang lain. Dalam getah tervulkan, atom-atom
sulfur membentuk rangkaian silang antara rantai-rantai panjang molekul getah
asli. Apabila diregangkan, rantai getah tervulkan tidak boleh mengelangsor di
antara satu sama lain dan terpaksa balik semula kepada bentuk asalnya oleh
rantai silang atom sulfur. Akibatnya getah tervulkan menjadi lebih keras, lebih
kenyal dan kurang melekit apabila panas.
kenyal dan boleh diregang
reaktif kepada agen kimia seperti minyak, gris dan petrol
fleksibel kerana ia adalah satu termoplastik yang lembut dan mengeras
bila berlaku pemanasan, boleh cair dan terbentuk semula untuk diguna
tidak telap air. Ini menjadikannya suatu penghalang yang sangat baik
terhadap patogen seperti virus HIV yang menyebabkan AIDS.
Peka kepada penipisan ozon disebabkan oleh kehadiran ikatan berganda dalam s
Getah asli yang digunakan untuk membuat objek adalah seperti berikut:
• hos air
• gelang getah
• tumit kasut
• sarong tangan, pembedahan dan perubatan
• assesori enjin untuk mengurangkan getaran dan hentakan
Getah tervulkan digunakan untuk membuat objek seperti:
pengelap cermin kereta
penyumbat dan pengalas pengantungan (Seals and suspension mountings)
Getah sintetik seperti neoprene digunakan untuk membuat objek seperti:
tali pinggang kereta
paip atau hos fleksibel untuk industri petrol
bahan-bahan penebat untuk sambungan elektrik di tempat yang ada bahan
Istilah 'polimer' berasal dari perkataan Greek, 'poli' bermaksud 'banyak' dan 'mer'
bermaksud 'bahagian'. Polimer adalah molekul berantai panjang yang dibentuk
daripada penggabungan secara berulangan beberapa unit-unit kecil yang dipanggil
Sutera merupakan gentian protein semula jadi yang diperolehi dari kokon yang
dibuat oleh larva ulat sutera yang diternak dalam kurungan. Sutera sebenarnya
diperbuat daripada protein yang dirembeskan dalam keadaan bendalir ulat sutera
Sifat-sifat sutera adalah seperti berikut:
• bersinar semula jadi
• mempunyai tekstur licin dan lembut
• tahan asid mineral
• mempunyai kelembapan yang baik
• rintangan rendah terhadap pendedahan cahaya matahari
• keanjalan sederhana dan rintangan kedutan
• paling kuat antara semua gentian semula jadi tetapi kehilangan 20% kekuatan
Kapas adalah serat lembut yang tumbuh di sekitar biji benih pokok kapas, pokok
renek yang berasal dari kawasan tropika dan subtropika di seluruh dunia, termasuk
Afrika, India dan Amerika. Kapas adalah tanaman musim panas, jadi ia mesti
ditanam di kawasan-kawasan yang mempunyai kurang taburan hujan. Gentian yang
paling popular diputar ke dalam benang dan digunakan untuk membuat tekstil yang
lembut, di mana ianya merupakan gentian kain semulajadi yang paling meluas
digunakan dalam pakaian hari ini.
Sifat-sifat kapas adalah seperti berikut:
• tahan Lama
• baik unuk mencetak
• penyerap kelembapan yang baik
• daya tahan rendah (mudah berkedut)
• rintangan tinggi terhadap pelarut organik dan alkali
Kapas digunakan dalam pembuatan:
• Penapis kopi
• Seluar Jeans
• Putik kapas dan swab
Benang bulu adalah gentian yang berasal dari sel-sel kulit yang khusus, yang
dipanggil folikel. Ia diperolehi dari haiwan dalam keluarga Caprinae, terutamanya
kambing biri-biri, tetapi rambut dari sesetengah spesis mamalia lain seperti kambing,
llamas dan arnab juga boleh dipanggil benang bulu. Benang bulu mempunyai
beberapa kualiti yang membezakan dari rambut atau bulu: ia kerinting, mempunyai
tekstur yang berlainan, anjal dan tumbuh dalam kelompok
Sifat-sifat dari benang bulu adalah seperti berikut :
• bahan-bahan panas
• gentian ketat berkerut
• Sel-sel luar gentian menangkis air sementara sel-sel dalaman menyerap
• Keanjalan-wol yang tinggi memiliki keupayaan yang lebih besar untuk kembali
ke panjang asal selepas diregangkan berbanding dengan mana-mana gentian
• Keupayaan penyerap yang tinggi, mampu mengekalkan sehingga 25 peratus
daripada berat dalam kelembapan.
• Pewarnaan benang bulu lebih unggul berbanding dengan gentian tumbuhan
dari segi kekayaan dan kecerahan warna.
Kertas adalah bahan yang boleh didapati dalam pelbagai jenis ketebalan dan berat
yang berbeza. Beberapa jenis kertas termasuk:
• kertas buku
• kertas inkjet
• kertas penunjuk pH
• kertas fotografi
• kertas biasa
• kertas kitar semula
• kertas beras
• kertas tuala
• kertas dinding
• kertas lilin
• kertas pasir
• kertas bersalut (permukaan berkilat dan matt)
• kertas biasa
• Berat Asas (GSM)
• Kecerahan, keputihan dan warna
• Kestabilan dimensi
• Kebolehan dilipat (lipatan Double)
• Kilat (Gloss)
• Mesin dan Haluan melintang
• ketelapan (porosity)
• pelbagai saiz / Cobb
• Kenyal (Pemanjangan)
• Rintangan mengoyak
• Suhu dan Kelembapan: keadaan Kertas
• Kekuatan permukaan
Langkah-langkah dalam proses membuat kertas:
• Pemprosesan pulpa menggunakan kimia atau mekanikal
• Penambahan bahan tambah
• Proses Akhir
Kertas boleh digunakan berdasarkan kepada pelbagai cirinya bergantung kepada
tujuan pengunaannya, seperti:
• Untuk menulis atau mencetak: sehelai kertas boleh menjadi dokumen; ini
mungkin untuk menyimpan rekod (atau dalam keadaan mencetak dari
komputer atau menyalin dari kertas lain: sebagai rekod tambahan) dan untuk
• Untuk mewakili nilai: wang kertas, nota bank, cek, baucar, tiket
• Untuk hiburan: buku, majalah, surat khabar, lukisan, seni
• Untuk pembungkusan: kotak beralur, beg kertas, sampul surat, tisu pembalut,
• Untuk pembersihan: kertas tandas, sapu tangan, tuala kertas, tisu muka
• Untuk pembinaan: kertas “mache” (paper mache), origami, quiling, kertas
• Lain-lain kegunaan: kertas pasir, kertas penyerap, kertas litmus, kertas
penunjuk universal, kertas kromatografi, kertas penebat elektrik, kertas turas