School Science Lessons
Chemistry
2025-11-24
Chemistry, Ad to Az

Aluminium

Contents

Aluminium
Contents
13.0.0 Aluminium properties
13.1.0 Aluminium compounds
13.2.0 Aluminium minerals
13.3.0 Aluminium experiments
13.4.0 Aluminium powder

Air
Anthraquinone
Antimony, Sb
Antimony (III) chloride
Antioxidantszzz
Aldosteronezz
Angelic acid
Anethofuran
Anethole
Antheraxanthin
Apigenin
Apigenin dimethylether
Apigeninglucoside
Apocynin
Aqua regia
Aqueous solutions
Arachidonic acid
Arbusculin A
Arctigenin
Arctiopicrin
Arrhenius equation
Arginine
Argon, Ar
Arsenic, Ar
Artabsin
Artemisinin
Ascaridole
Ascorbic acid
Asbestos
Asimicin
Aspartic acid
Asphalt
Atoms
Atorvastatin
Autocatalysis
Aurantinidin
Aureusidin
Avenanthramide A
Azadirachtin
Azafrin
Azetidine-2-carboxylic acid
Azide

Air
The composition of air is varies, so "pure air" is usually air which contains no dust, aerosols and gaseous contaminants from industry.
The composition of the major components of dry air is as follows:
nitrogen 78.084 %, oxygen 20.946 %, argon 0.934 %, carbon dioxide 0.033 %, neon 0.0018 %, helium 0.000524 %, methane 0.00016 %, krypton 0.000114 %, hydrogen 0.00005 %, nitrous oxide 0.00003 %, xenon 0.0000087 %.
However, the concentrations of carbon dioxide, methane, nitrous oxide, the chlorofluorocarbons and gases from industry are increasing.
Air which is free of most pollution may be used as a reference sample for the calibration and operation of instruments, and may be purchased commercially under the designation of "zero air". Colorless, odourless carbon dioxide (CO2) gas, is the major carbon-containing product of combustion of carbon compounds.
It is removed from the atmosphere by the photosynthetic cycle in plants, which converts it into carbohydrate and other organic molecules, and release oxygen into the atmosphere. Carbon dioxide is also removed in the oceans, where it is converted to carbonate deposits.
The concentration of carbon dioxide in the atmosphere varies with its position on the earth, season, and time of day.
Its average mixing ratio in air has increased from about 315 to 340 ppmv during the last 25 years, as a result of increased burning of fossil fuels.
Colorless, odourless carbon monoxide (CO) gas is highly poisonous even at the level of 0.2% in air.
It is a product of the incomplete combustion of hydrocarbon fuels.
It is also formed in the atmosphere by the oxidation of methane and its oxidation product formaldehyde (CH,O).
The mixing ratios of CO in air is usually about of 100 ppbv near sea level.

Anthraquinone
Anthraquinone, C14H8O2, C6H4(CO)2C6H4, polycyclic aromatic hydrocarbon, light grey crystal or powder
It is a yellow crystalline solid, and is used to make dyes for textiles and for paper making.
Cochineal
A tetrahydroxyanthraquinone occurs in the plant pigment cochineal, a natural dye isolated from insects.
For example, (Dactylopius coccus), on the prickly pear cactus in Mexico.
Cochineal contains carminic acid, C22H20O13, Natural red 4, Coccinellin.

Antimony, Sb
Antimony, Table of the Elements
Antimony, RSC
Antimony, Sb (Greek anti monos not alone) (Latin stibium, "Sb"), stibium, antimony regulus, silver-white, brittle metalloid, powder, shot
It is used in plastics, textiles, rubber, adhesives, pigments, papers, and tropical parasite medicine.
Antimony occurs in coal and petroleum, but rarely as the metal, usually in hydrothermal veins combined with other elements, e.g. sulfur.
Alloys occurs in solder, sheet, pipe, bearing and type, blue white silvery metal with a gleaming surface (star antimony) or, as a grey powder, (grey wolf), hence the name "anti monos" (against singleness), because it has two forms.
It burns in air, but has no reaction with water or dilute acids, attached by halogens and oxidizing acids, poor conductor of heat and electricity, It is used in alloys for cable covers, pewter and lead cell accumulator plates, donor impurity in silicon chips, radioactive isotopes to produce neutrons.
Antimony black is powdered antimony used to give plaster casts a metallic look.
Antimony and antimony salts are available from artists' suppliers.
Pewter, malleable alloy of mostly tin, + some copper, antimony, and bismuth
It was used in emetic medicine, but is toxic in excess.
It was in the black powder eye makeup, kohl, as used by Jezebel in the Bible (2 Kings 9: 30).
Naples yellow, antimony white and antimony black are all highly toxic cumulative poisons.
Yellow antimony lead paint is said to have been used on Nebuchadnezzar's "Hanging Gardens of Babylon".
Atomic number: 51, Relative atomic mass: 121.75, RD 6.68, MP = 630.5oC, BP = 1750oC.
Specific heat capacity: 210 J kg-1 K-1.
7.1.6.8 Chemical changes, heat metals in chlorine, (See:2.)
32.5.3.2 Lead-acid battery secondary cell, (See: 3. lead-antimony grid)
33.7.6.2 Peltier effect, (See: 3.)
12.2.1 Reactions of antimony
35.2.65 Stibnite, Sb2S3, the most important mineral source of antimony, (Geology)
12.11.2a Tests for antimonates, borates, oxalates
12.11.3.12 Tests for antimony
12.11.3.2 Tests for metals with flame tests, (See: Antimony)
12.14.17 Zinc powder with iodine solution, (See: 3. Repeat with Antimony.)
Antimony compounds are high toxicity chemicals.
Antimonic compounds (+5 oxidation state), e.g. antimony (V) chloride, SbCl5
Antimonous compounds (+3 oxidation state) e.g. antimony (III) chloride, SbCl3

Antimony (III) chloride
Antimony (III) chloride, SbCl3, antimonous chloride, antimony trichloride, butter of antimony, Harmful, Corrosive
Antimony is NOT recommended for use in junior secondary science classes.
Antimony (III) fluoride, SbF3
Antimony (III) sulfide, SbS3, is added to some match heads to increase the vigour of burning.
Antimony (III) oxide, antimony trioxide, senarmonite, velentinite
Antimony (V) chloride, antimonic chloride, antimony pentachloride, SbCl5
Antimonial lead, lead-antimony alloy, bouronite
Antimony bloom, Sb2O3, Valentinite, weathering product of antimony ores
Antimony oxysulfide, antimony red, vermilion
Antimony pentfluoride, SbF5 + acid, HF --> super acid mixture, pH -31
Antimony trisulfide, antimony black, white colour in fireworks
Hydrolysis of antimony chloride: 17.5.5
Potassium chlorate in pyrotechnic flash powders: 15.4.14 (Antimony trisulfide and chlorate)
Prepare iron (III) chloride, FeCl3: 12.19.8.3 (See: 1. antimony chloride)
Separate to metals by reduction of metal oxides, charcoal blocks (ores): 10.10.0 (See 3. Warning!)

Antioxidants
Antioxidants: See diagram 19.2.1.6
Antioxidants, vitamin E: 9.6.5
Antioxidants, food additives: 19.1.4
Clove oil, eugenol: 16.3.6.9
Free radicals and antioxidants: 9.6.7
Gallic acid: 16.3.6.19
Antioxidants occur in Garlic, (Allium sativum var. sativum), Amaryllidaceae and in Creosote bush, Larrea tridentata, Zygophyllaceae.
Ghee (Butter and butter oil)
Naphthol
Propyl gallate: 16.3.6.20
Rancidity of fats: 3.9.9
Sequestrants: 19.1.8
Vitamin C (ascorbic acid): 9.6.3
Vitamin E: 9.6.5

Aldosterone
Aldosterone, C21H28O5, is a hormone secreted by adrenal cortex to regulate electrolyte and water balance.
It increases the renal retention of sodium and the excretion of potassium.
It is a mineralocorticoid hormone produced by aldosterone synthase in the zona glomerulosa of the adrenal cortex.
It regulates the retention of sodium, the secretion of potassium, and water reabsorption, all of which may result increased blood pressure.
Aldosterone may cause coronary inflammation, cardiac hypertrophy, myocardial fibrosis, ventricular arrhythmias, and ischemic and necrotic lesions.

Angelic acid
Angelic acid, C5H8O2, 2-Methylisocrotonic acid, monocarboxylic unsaturated organic acid, corrosive, acid taste, pungent sour odour, former sedative
It crystallizes as colourless monoclinic prisms.
It occurs in Angelica, Angelica archangelica, Apiaceae.

Anethofuran
Anethofuran, C10H16O, monoterpene ether, dill ether, flavouring agent, colourless to pale yellow clear liquid.
Up to 20% occurs in dill leaf oil, in Black caraway (Nigella sativa), and in Dill, (Anethum graveolens), Apiaceae.

Anethole
Anethole, C10H12O, CH3CH=CHC6H4OCH3, trans-Anethole, monoterpene, a monomethoxybenzene, white crystals or liquid, odour of anise oil, sweet taste
4-propenylanisole, isoestragole, anise camphor, unsaturated ether, hydrophobic terpene, very slightly soluble in water.
Anethole is very sweet (13 times sweeter than sugar), aromatic flavour of Anise and Fennel, odour of anise oil.
Anethole occurs in Anise (Pimpinella anisum), Fennel (Foeniculum vulgare), Aniseed myrtle (Syzygium anisatum), and in Star anise (Illicium verum).
See diagram: Anethole.
Oil of aniseed is sold as Aniseed Essential Oil.
Oil of aniseed occurs in alcoholic beverages, absinthe, anisette (anis), arak, champurrado (atole de anis), ouzo, pastis, Pernod, raki sambuca, non-alcoholic root beers.
Anethole occurs in essential oils of Star Anise, Anise seed oil, Sweet Fennel, flavour of of candy, ice cream, and chewing gum.
Anethole is estrogenic at lower concentration, but cytotoxic at higher concentrations.
Anethole is anti-microbial and anti-fungal, and is used as insecticide, mosquito repellent.
7.6.01 Ouzo effect, microemulsions, hydrophobic terpene.

Antheraxanthin
Antheraxanthin, C40H56O3, an epoxycarotenol, a neutral yellow plant pigment
It occurs in (Ramalina capitata), (Perilla frutescens). and in Euglenophyta algae.

Apigenin
Apigenin, C15H10O5, versulin, apigenol, a trihydroxyflavone, anti-inflammatory, anti-tumor, inhibit melanoma growth, inhibits growth of cancer cells.
It occurs in parsley, thyme, peppermint, chamomile, lemon balm, vervain, yarrow, (Anthemis nobilis), and in (Limonium axillar)e.

Apigenin dimethylether
Apigenin dimethylether, C17H14O5, Apigenin (7,4'-dimethyl ether), a monohydroxyflavone.
It is generated by cyp2c9 and cyp2c19 enzymes in humans.
See diagram 14.03, Apigenin dimethylether

Apigeninglucoside
Apigeninglucoside, C21H20O10, apigenin, 6-C-glucoside, isovitexin, saponaretin, a trihydroxyflavone, alpha-glucosidase, and irritant.
It occurs in Cosmos bipinnatus, nodulation signal to Rhizobium leguminosarum

Apocynin
Apocynin, C9H10O3, acetovanillone, aromatic methyl ketone, acetophenone.
It is a non-narcotic analgesic, non-steroidal anti-inflammatory, antirheumatic, peripheral nervous system drug.
As a folk medicine, it is used to treat bronchial asthma and pulmonary diseases.
It occurs in Dogbane (Apocynum cannabinum), Kutki (Nepal) (Picrorhiza kurroa), and in Orris, (Iris florentina)

Aqua regia
Aqua regia, "royal water", [1 part concentrated HNO3 + 3 parts concentrated HCl], [3, 1 (v/v) HCl/HNO3]
[Sold as, HNO3 70%, HCl >25%], dissolves gold so "king of metals" to form AuCl4.
Most other acids cannot attack gold, so aqua regia is called "the acid test" of gold.
Aqua regia dissolves platinum to form H2PtCl6.
Aqua regia, "royal water", dissolves gold (3 vols concentrated HCl + 1 vol concentrated HNO3)

Aqueous solutions
The states of matter are solid (s), liquid (l), gas (g), aqueous solution (dissolved in water) (aq).
An aqueous solution is a solution in water.
In this document "solution" is always an aqueous solution unless otherwise specified.
So a sugar solution contains sugar dissolved in water, but a solution of liquid sucrose contains no water.

Arachidonic acid
Arachidonic acid, C20H32O2, unsaturated, essential long-chain fatty acid, in animal and human fat and organs, in phosphatides
It is formed from dietary linoleic aci, in biosynthesis reactions.

Arbusculin A
Arbusculin A, C15H22O3, Eudesmanolide, (4-epiarbusculin A), sesquiterpene lactone, organic heterotricyclic compound, tertiary alcohol, nhibits melanin synthesis.
Arbusculin A is a plant growth inhibitor, and it occurs in (Artemisia arbuscula), and in (Saussureae radix).

Arctigenin
Arctigenin, C21H24O6, a lignan, antiviral, anticancer
It occurs in Arctium lappa, iand Saussurea heteromalla.

Arctiopicrin
Arctiopicrin, C19H26O6, germacranolide, sesquiterpene lactone, bitter glycoside, antibacterial
It occurs in Arctium, and in (Centaurea melitensis).

Arrhenius equation
Chemical form, k =Ae-Ea/(RT)
Where k = rate constant of chemical reaction, Ea = activation energy, energy per mole, T = absolute temperature, R = universal gas constant, where A is the prefactor k is the number of collisions that cause a reaction per second.
The rate constant, k, of a given reaction is a function of temperature.
In general, starting from room temperature, reaction rate doubles for every 10oC rise in temperature.
Svante Arrhenius, Sweden, 1889, discovered that electrolytes conduct electricity, because they contain ions.
He was interested in the kinetics of chemical reactions.
The Arrhenius model is used to explain the behaviour of strong and weak acids and bases in aqueous solutions.

Arginine
Arginine, C6H14N4O2
Prepare minimal agar medium
Prepare MS agar solution
Structure of DNA: 9.4.3
Tests for proteins, Sakaguchi's arginine test: 9.4.6
D,L-arginine (SIGMA No. A 4881), microbiology chemical
It occurs in cassava and egg yolks.

Argon, Ar
Argon, Table of the Elements
Argon, RSC
Argon, Ar (Greek argos idle, because this noble gas will not react with other substances)
Agon is a non-metal, inert, colourless, odourless, noble gas at room temperature and pressure, 0.93% of the air, extracted from liquid air.
Chemically inactive, no compounds, monatomic gaseous element, in incandescent light bulbs, fluorescent tubes, lasers, and welding.
Most abundant noble gas, 0.9% of atmosphere by volume.
The only neutral compound of argon is argon fluorohydride, HArF, but the compound collapses at very low temperature.
First "noble" gas, discovered by William Ramsay in 1894.
Argon means "lazy".
Atomic number: 18, Relative atomic mass: 39.948, RD 1.40 (87 K), MP= -189oC, BP = -186oC.
Specific heat capacity: 519 J kg-1 K-1.
Gas, Molecular weight, Density, (Table 1)
E 938 Packaging gas
It is hard to find a new chemistry joke, because all the best jokes Argon!

Arsenic, Ar
Arsenic, Table of the Elements
Arsenic, RSC
Chemicals Not permitted in schools, Australia: Arsenic compounds
12.3.0 Arsenic, Reactions of arsenic
12.11.3.8 Heat substances with charcoal and fusion mixture, (See: 2.)
35.2.9 Minerals containing arsenic, (Geology)
12.11.3 Tests for arsenates
Tests for arsenic: Heat with charcoal, light blue flame test if moistened with hydrochloric acid.

Artabsin
Artabsin, C15H20O3, a tricyclic sesquiterpene lactone, occurs in Wormwood (Artemisia absynthium).

Artemisinin
Artemisinin, C15H22O5, Qinghaosu, (8-Hydroxysantonin), sesquiterpenoid lactone, organic peroxide, flammable, environmental hazard, Chinese herbal medicine.
It is used to treat malaria, including chloroquine-resistant (Plasmodium falciparum), using artimisin-combination therapies (ACTs), and antihelmintic, schistosomiasis.
It is possibly colo-rectal anti-cancerous, but may damage the liver.
It was formerly used in the production of absinthe and nowadays used to flavour some vermouths, and occurs in Sweet wormwood, (Artemisia afra).

Ascaridole
Ascaridole, C10H16O2, bicyclic monoterpene, colourless liquid, soluble most organic solvents, unstable, may explode when heated or ith organic acids, pungent smell.
It occure in cardamom, tea tree oil, major constituent of oil of boldo (Peumus boldus) and Mexican tea, epazote (Dysphania ambrosioides).
Boldo, (Peumus boldus), Monimiaceae.

Ascorbic acid
Ascorbic acid, C6H8O6, powder pillows, L-ascorbic acid tablets, vitamin C
Dipsticks to test the ascorbic acid, content of food: 19.1.10
Tests for phosphate ions in water: 18.4.1, (Add crystals of L-ascorbic acid)
Tests for carbohydrates, Molisch's test: 9.3.7
Tests for vitamin C, DCPIP: 9.3.21

Asbestos
Asbestos, hydrous magnesium silicate, asbestos fibre, mineral wool: 35.20.3, (Geology)
Asbestos, Crocidolite asbestos and blue asbestos, Not permitted in schools
Asbestos, store demonstration asbestos specimens in sealed containers, or embedded in plastic
Asbestos, 5% platinized, platinized asbestos
Asbestos, (Greek amiantos undefiled, i.e. not burnt in a fire)

Asimicin
Asimicin, C37H66O7, annonin VI, Rolliniastatin, Bullatacin, Squamocin, polyketide
It occurs in alcoholic beverages, in biriba Rollinia mucosa, in sugar apple Annona squamosa, in custard apple Annona reticulata.

Aspartic acid
Aspartic acid, C4H7NO4, L-Aspartic acid (S)-(+)-aminosuccinic acid (S)-aminobutanedioic acid
Aspartic acid L-, HOOC-CH2-CH(NH2)-COOH, (2-aminopentanedioic acid), glutamic acid, L-aspartic acid
Aspartic acid (Table of amino acids)
Aspartic acid, DNA codons
Amino acids: 16.1.0, (See: Type 4.)
Separate amino acids with paper chromatography: 10.2.6
Leucine, (See: Solution a3

Asphalt
Asphalt can refer to natural bituminous pitch, e.g. the Trinidad Pitch Lake, or,
the fraction of crude oil produced by distillation, or,
the "hot mix" mixture of aggregate and bitumen used to surface roads, paths and school playgrounds.
The residue of petroleum distillation is called asphalt, but also called "tar".
Asphalt, (bitumen tar, pitch), is black plastic solid from final residues after volatile substances are removed by fractional distillation of natural petroleum.
Asphalt is used for road construction and sealing roofs.
Asphalt splinters when smashed, but flows gradually.
Asphalt is a natural organic material, often occurring in tar pits, with a hydrocarbon base that softens with heat.
Asphalt has been used for thousands of years for basins, impermeable water ways, sealing roof shingles, and caulking wooden ships.
Bitumen is any naturally occurring asphalt or any black, viscous hydrocarbon mixture.
Bituminous coal burns with a bright smoky flame.
In the days of sail, British sailors were called "tars" or "jack tars", because they used tar to caulk the seams of ships or,
because they wore clothes made of tarpaulin combined with tar.
Asphalt: 16.8.1, Fractional distillation of crude oil
Bitumen foaming and bitumen decay: 24.1.6
Test for synthetic fibres: 4.3.0 (See: 4.3.15 Polyethylene, Burning test
Coal tar products, creosote: 16.14.1
Ethylbenzene, C8H10
Shear-thickening, stir-thickening, dilatant fluids, rheopectic fluids: 13.6.5 (See 2. Rheopectic fluids)
Solar ultraviolet radiation and skin cancer: 37.1.5
Sulfonated asphalt is an oil drilling additive.

Atoms
Atoms: 7.4.8
27.195, Atomic Absorption Spectroscopy, (AAA)
2.4.0, Atomic mass unit, (amu)
2.2.0, Atomic number and mass number
2.3.0, Atomic weight
Atomic absorption spectroscopy, AAA: 27.195
Atomic mass, atomic weight: 5.3.2
11.2.3, Construct molecular models
Deuterium

Atorvastatin
Atorvastatin, C33H35FN2O5, synthetic lipid-lowering agent, inhibits hepatic hydroxymethyl-glutaryl coenzyme A (HMG-CoA)
It lowers plasma cholesterol and lipoprotein levels.
Atorvastatin calcium trihydrate salt, [C33H34FN2O5.0.5Ca.1.5H2O]

Autocatalysis
17.3.5 Ethyl acetate with sodium hydroxide, autocatalytic hydrolysis
17.3.7 Oxalic acid with potassium manganate (VII), autocatalysis
17.3.9 Potassium bromate with propanedioic acid, double autocatalytic reaction, oscillating reaction

Aurantinidin
Aurantinidin, C15H11O6+, 6-Hydroxypelargonidin, is an hydroxyflavonoid, anthocyanin, water-soluble, red plant dye.
It occurs in Impatiens, and Alstroemeria

Aureusidin
Aureusidin>, C15H10O6, an hydroxyaurone, anthocyanin
It occurs in Snapdragon, (Antirrhinum majus), Plantaginaceae.

Avenanthramide A
Avenanthramide A, C16H13NO5, [(Z)-N-Coumaroyl-5-hydroxyanthranilic acid]
It occurs in cereals, in oats (Avena sativa)
It is an anti-inflammatory, antioxidant, anti-itch, antiatherogenic, oat kernel extracts used for skin care and sun care products.

Azadirachtin
Azadirachtin A, C34H44O16, bioneem, NeemAzal, tetra, acetate ester, heterotetracyclic compound, methyl ester, yellow-green powder.
It has a strong garlic / sulphur odour, natural pesticide, insect antifeedant, commercial insecticide, hepatoprotective, environmental hazard.
It occurs in Neem tree (Azadirachta indica), Meliaceae.
See diagram: Azadirachtin.

Azafrin
Azafrin, C27H38O4, escobedin, an xanthophyll carotenoid, escobedin, sesterterpenoid
It occurs in Azafranillo and in (Escobedia scabrifolia).

Azetidine-2-carboxylic acid
Azetidine-2-carboxylic acid, C4H7NO2, is an amino acid, an azetidinecarboxylic, corrosive, irritant, a plant non-protein amino acid, teratogenic agent.
It causes production of abnormal proteins with impaired biological activity.
It occurs in common beet, in lily-of-the-valley roots and leaves of (Convallaria majalis), (It isbanned by FDA from food use in USA.).

Azide
Azide compounds, (N3-), or (-N3), (-N=N+N-)
Azide compounds: 16.2.5.1
Azide, organic azide, R-N=N+N-, hydrazoic acid HN3
Azide (azido), N-N2-, monodentate ligand

13.1.0 Aluminium compounds
Can, beer can, beverage can
35.2.11 Bauxite
13.1.1 Aluminium acetate
13.1.2 Aluminium ammonium sulfate
13.1.3 Aluminium bromide
13.1.4 Aluminium carbide
13.1.5 Aluminiumchloride
13.1.6 Aluminium fluoride
13.1.7 Aluminium hydroxide
13.1.8 Aluminium nitrate
13.1.9 Aluminium oxalate
13.1.10 Aluminium oxide
13.1.11 Aluminium phosphate
13.1.12 Aluminium phosphide
13.1.13 Aluminium potassium sulfate
13.1.14 Aluminium sulfate
13.1.15 Aluminium silicate
13.1.16 Alum
13.1.17 Anti-bumping granules

13.2.0 Aluminium minerals
13.2.1 Alnico magnets
13.2.2 Bauxite
13.2.3 Cryolite
Feldspars, (Geology)
13.2.4 Kyanite
13.2.5 Stilbite
13.2.6 Zeolite

13.3.0 Aluminium experiments
13.3.1 Alumina as a catalyst in the cracking process
13.3.2 Aluminium chloride with water
13.3.3 Aluminium sulfate reactions
13.3.4 Aluminium with acids
13.3.5 Aluminium with sodium hydroxide
13.3.6 Aluminium with sulfur
13.3.7 Bauxite digestion
13.3.8 Burn aluminium in oxygen
13.3.9 Corrosion of aluminium
13.3.10 Heat aluminium foil
13.3.11 Iodine with aluminium
13.3.12 Tests for aluminium
13.3.11 Tests for aluminium compounds
13.3.12 Tests for aluminium compounds in solution
13.3.15 Thermite reaction

13.0.0 Aluminium properties
Aluminium, Table of the Elements
Aluminium RSC
1. Aluminium, Al (Latin alumen bitter salt, referring to alum), (US Aluminum), Aluminium ion, Al3+
In 1990, The International Union of Pure and Applied Chemistry (IUPAC) confirmed the use of the spelling "aluminium".
However, people in the US are accustomed to using the spelling "aluminum".
Aluminium is a silver, light, ductile, malleable, metal, with mechanical strength.
Aluminium compounds are abundant.
Aluminium is extracted by electrolysis from the main aluminium ore bauxite dissolved in cryolite.
Bauxite is 8% of the earth's crust so aluminium is the most abundant element in the Earth's crust.
Atomic number: 13, Relative atomic mass: 26.9815, r.d. 2.70, m.p. = 660 oC, b.p. = 2470 oC, E 173
Specific heat capacity: 900 J kg-1 K-1
Aluminium availability:
Aluminium, Al, metal filings, ion Al3+, granules (stabilized), pellets (coated) (powder 1396), Flammable powder
Aluminium is available as foil, sheet, and wire.
Aluminium foil, "Alfoil" cooking foil, 300 width × 150 m roll, "Alfoil" disposable containers, rectangular 120 mm × 175 mm, round 120 mm diameter.
Aluminium ignots, 99.7% purity
Aluminium reagent test kit, No. 1 tablets, No. 2 tablets, AAS Std, leaf, flakes, sheet, drink-can, ingot, wire
Aluminium, although toxic, is not a heavy metal.
Low cost: Aluminum kitchen foil, aluminum drink cans (beverage cans, plastic coated inside), aluminum window screen frames
Duralumin, alloy of Al + Cu + Mg
Aluminium uses
Aluminium metal is not tarnished in air, because it forms protective oxide that prevents further oxidation.
The aluminium foil used in home kitchens from grocery stores and the aluminium wire and aluminium sheeting from hardware stores are all pure aluminium.
Most reactions of aluminium are inhibited by a surface coating of aluminium oxide.
This is the reason that such an active metal as aluminium can be used widely for construction and for containers.
Alfoil disposable containers + lid, 105 mm width × 184 mm depth × 38 mm height.
Aluminium foil is used to clean pots and barbecue grill on picnics.
Rub rust from and polish chromium plating, seal used paint tins and planting pots, catch baking drips.
Aluminium is protected by layer of oxide that can be thickened if an anode in electrolytic cell, i.e. anodized then can be coloured.
It is malleable, low density, is used in "Alfoil" cooking foil, drink-cans, saucepans, duralumin (alloy of Al + Cu, Mg), aircraft bodies and struts, motor vehicle parts.
Aluminium food additive, E173 (colour: metallic) (Banned, some countries, excess unsafe)
Heated powder forms oxide.
Excess aluminium may cause short term toxicity, e.g. aluminium sulfate in drinking water, corroded cooking utensils with acidic foods, alum treatment of water.

13.1.1 Aluminium acetate
Aluminium acetate, Domeboro, C6H9AlO6, Al COOCH3)3, aluminium ethanoate, topical astringent, antiseptic agent.

13.1.2 Aluminium ammonium sulfate
Aluminium ammonium sulfate (dodecahydrate), (AlNH4(SO4)2.12H2O), ammonium alum, food additive, E523, buffer, stabilizer.

13.1.3 Aluminium bromide
Aluminium bromide, AlBrx, commonly aluminium tribromide (Al2Br6), used in Friedel–Crafts reactions for production of polystyrene.

13.1.4 Aluminium carbide
Aluminium carbide, (Al4C3), yellow-brown crystals, reacts with water to give methane.
Al4C3 + 12 H2O → 4 Al(OH)3 + 3 CH4

13.1.5 Aluminium chloride
Aluminium chloride, (AlCl3), anhydrous, covalent, Toxic if ingested, but Solution < 5%, Not hazardous
Aluminium chloride, hydrated, (AlCl3.6H2O), the anhydrous AlCl3 is covalent, for 0.1 M solution, 24 g of hydrated salt in 1 Litre water.
Aluminium chloride with water: 13.1.8

13.1.6 Aluminium fluoride
Aluminium fluoride, aluminum trifluoride, AlF3, odourless white powder, with cryolite used in production of aluminium by electrolysis.

13.1.7 Aluminium hydroxide
Aluminium hydroxide, Al(OH)3, occurs as mineral gibbsite (hydrargillite), E173 food additive, antacid, many biomedical uses.
Prepare aluminium hydroxide precipitate: 7.6.4

13.1.8 Aluminium nitrate
Aluminium nitrate, Al(NO3)3, hydrated aluminium nitrate, aluminium nitrate nonahydrate, Al(NO3)3.9H2O harmful if ingested.
Crystals are white and soluble in water. It is used in tanning, antiperspirants, to inhibit corrosion.
Aluminium nitrate with sodium hydroxide: Al(NO3)3 + 3NaOH --> Al(OH)3 + 3NaNO3.

13.1.9 Aluminium oxalate
Aluminium oxalate, C6Al2O12, strong dicarboxylic acid, occurs in many plants, produced in the human body and excreted in the urine.

13.1.10 Aluminium oxide
Aluminium oxide, (Al2O3), alumina, orundum, amphoteric oxide, almost insoluble in water (used for leaching minerals).
lung irritation, toxic if inhaled, alumina (porcelain), amphoteric, corundum (hardness 9, abrasive, sand paper, in red ruby, in blue sapphire).
Diamantine, emery powder (abrasive), corroded aluminium (bauxite, hydrated aluminium oxides, (Al2O3.nH2O + laterite).
Alumina hydrate for craft, alumina has amorphous or crystalline state in corundum and bauxite powder used for thin-layer chromatography plates.
Low cost purchase from pottery supplies store
Amphoteric oxides react with both acids and bases, e.g. (Al2O3), PbO, SnO, ZnO.
Their hydroxides are also amphoteric.
Alumina polishing powder

13.1.11 Aluminium phosphate
Aluminium phosphate, AlO4P, berlinite mineral. used in cake mixes and baking powders, and as an antacid and adsorbent of toxoids.

13.1.12 Aluminium phosphide
Aluminium phosphide, AlP, fumigant, grey-yellow crystalline solid, phosphideis used to destroy pests in grain silos.
It has a strong smell like garlic or rotten fish and should be tranported in the open on the back of a vehicle.
It reacts with water to give very toxic phosphine gas.
AlP + 3 H2O -->Al(OH)3 + PH3

13.1.13 Aluminium potassium sulfate
Aluminium potassium sulfate, potassium aluminium sulfate, alum, aluminium potash, potash alum, Harmful
Potassium aluminium sulfate, aluminium potassium sulfate, alum, potash, potash alum
Potassium alum, "alum", potash alum, potassium aluminium sulfate, Al2(SO4)3.K2(SO4).24H2O, K2SO4.Al2(SO4)3.24H2O, KAl(SO4)212(H2O)
Kalinite, Aluminium potassium sulfate
Aluminium potassium sulfate-12-water Aluminium potassium sulfate-12-water, aluminium potassium sulfate hydrated
Al2(SO4)3.K2(SO4).24H2O or AlK(SO4)2.12H2O or KAl(SO4)2.12H2O
Aluminium potassium sulfate-12-water, potash alum, "alum", aluminium potash
Alum, potassium alum, "common alum", potash alum, hydrated potassium aluminium sulfate, hydrated aluminium potassium sulfate
Aluminium potassium sulfate 12-hydrate, kalinite, a double sulfate of aluminium, the "alum" sold at grocery shops
Aluminium potassium sulfate is very astringent and is used for purifying water.

13.1.14 Aluminium sulfate
Aluminium sulfate, Al2(SO4)3, hydrated aluminium sulfate Al2(SO4)3.18H2O, (NOT "alum"!)
Aluminium sulfate Al2(SO4)3 xH2O, aluminium sulfate hydrate, cake alum, Harmful to eyes, Harmful if ingested
Aluminium sulfate octadecahydrate Al2(SO4)3.18H2O, wrongly called "alum", E520, foam agent in fire extinguishers, water filter powder.
It is used as a flocculation agent, food additive E520, modifier, precipitator in sewage treatment, mordant, paper sizing.
For 0.l M solution, use 66 g of hydrated salt in 1 L water.
Aluminium sulfate reactions: 12.3.3
Aluminium sulfate with clay suspensions: 7.6.3

13.1.15 Aluminium silicate
Aluminium silicate, Al2SiO5, fibrous material, mineral andalusite Al2O3·SiO2

13.1.16 Alum
The original "alum" was the hydrated double salt of aluminium and potassium with colourless octahedral crystals and an astringent taste.
It was used for mordants before dyeing cloth.
Later the term "alum" was used to describe similar double sulfates where other elements, or radicals replaced aluminium or potassium.
So an "alum" is a hydrated aluminium potassium sulfate and related minerals.
Some plants with astringent roots are called "alum roots".
Aluminium ions form alums that are complex hydrated metal sulfates that contain 12 or 24 H2O.
"Alum" often refers to potassium alum, potash alum, potassium aluminium sulfate, aluminium potassium sulfate
KAl(SO4)2·12H2O, AlK(SO4)2.12 H2O, KAl(SO4)2, AlK(SO4)2, K2SO4.Al2(SO4)3.24H2O, AlKO8S2.
Soda alum, Na2SO4.Al2(SO4)3.24H2O
Potassium alum, "common alum", potash alum, hydrated potassium aluminium sulfate, aluminium potassium sulfate 12-hydrate.
Kalinite, a double sulfate of aluminium, the "alum" sold at grocery shops.
Aluminium potassium sulfate is very astringent and is used for purifying water.
Al2(SO4)3.K2(SO4).24H2O or AlK(SO4)2.12H2O or KAl(SO4)2.12H2O
Aluminium potassium sulfate is a buffer and firming agent, E522.
Other alums:
Ammonium alum, Aluminium ammonium sulfate dodecahydrate, AlNH4(SO4)2.12 H2O, AlH28NO20S2, NH4Al(SO4)2.12H2O, Tschermignite
Sodium alum, Soda alum, Sodium aluminum sulfate dodecahydrate, AlNa(SO4)2· nH2O (n = 0 or 12), AlH24NaO20S2, Na2SO4.Al2(SO4)3.24H2O
Chrome alum KCr(SO4)2·12H2O, CrK(SO4)2.12H2O, K2SO4.Cr2(SO4)3.24H2O, chromium (III) potassium sulfate, potassium chromium sulfate
It is used for for tanning, mordant, photography, purple or violet-red octahedral crystals.
Industrial alum (papermaker's alum) Al2(SO4)3·nH2O
Tschermignite, NH4Al(SO4)2.12H2O, ammonium alum

13.1.17 Anti-bumping granules, boiling chips, alumina
Anti-bumping granules, boiling chips (- ceramic, silicon carbide, fused alumina)
Boiling chips, fused alumina or flower pot bits, prevent large bubbles of gas forming that could cause explosive emissions from a beaker containing heated solution.
Sudden formation of a large amount of vapour from the bottom of a heated vessel of liquid, rather than the usual controlled boiling causes explosions.
So boiling chips (anti-bumping granules) are added to chemical reactions to keep the bubbles small and aid steady boiling.
Hydrocarbons with longer chains have higher boiling points than with branched chains, because of more van der Waals intermolecular bonds between molecules.

13.2.1 Alnico magnets
Alnico magnets, ferromagnetic alloy, contains Al 8-12%, Ni 15-26%, Co 5-24% + in some forms Cu 6%, Ti 1%.
It is used at 500 oC to 800 oC to make strong permanent magnets for electric motors, refrigerator doors and radio speakers.

13.2.2 Bauxite
Bauxite, Al2O3 x2H2O, (hydrated aluminium oxide, Al2O3), is a residual sedimentary mineral.
It contains alumina and other oxides of aluminium in the amorphous or crystalline state.
So it is more a rock-like mixture than a mineral.
Bauxite is a mixture of iron and aluminium hydroxides and oxides.
It is usually formed by weathering in tropical regions.
It is the most important ore for production of aluminium.
Bauxite has non-metallic lustre, white streak, no good cleavage, can be scratched by the finger nail, white to brown grey colour, uneven fracture, specific gravity 2.0-2.5.

13.2.3 Cryolite
Cryolite, sodium aluminium fluoride, Na3AlF6, has colourless to white to yellow colour, and sometimes purple to black colour.
It has Mohs scale of hardness 2.5-3, white streak, greasy to glassy lustre, no cleavage, uneven fracture and specific gravity 2.95-3.0.
The refractive index is 1.34. so the specimen almost disappears in water.
It is a colourless rare mineral used as a flux in electrolytic production of aluminium from bauxite, and is manufactured synthetically.
Note the disappearance in water, no salty taste and density of the specimen.

13.2.4 Kyanite
Kyanite, Al2(O, SiO4), disthene, munkrudite, cyanite, rhaeticite (white grey kyanite), (Greek kyanos blue), is an aluminosilicate mineral.
Mohs scale of hardness 4-5 and 6.5-7 depending on the direction of the cleavage planes, colourless streak, vitreous lustre.
Found in aluminium-rich metamorphic pegmatites and sedimentary rock.
Used in refractory and ceramic products, electrical insulators, abrasives, gemstones.
Elongated, columnar crystals.
Anisotropic, i.e. two different harnesses on perpendicular axes.

13.2.5 Stilbite
Stilbite is a member of the zeolite group, lamellar zeolite, hydrated sodium calcium aluminium silicate, Ca(Al2Si7O18).6H2O.
Stilbite, hydrated sodium calcium aluminium silicate, has more than one chemical formula, e.g. Na2CaK2Al2Si7O18.7H2O, or
NaCa2Al5Si13O3614H2O, has white to pink to yellow colour, Mohs scale of hardness 3.5-4, white streak, glassy to pearly lustre,
good cleavage in one direction, specific gravity 4.56.
Note how thin crystals stick together like a sheaf of wheat, lustre and density of the specimen.

13.2.6 Zeolite
Zeolite (T5O10, T10O20 chains), e.g. tetrapropylammonium (TPA) ZSM-5, clinoptilolite
Zeolite, e.g. tetrapropylammonium (TPA)ZSM-5, is a group of natural or synthetic hydrated aluminium silicates, appear to boil when heated in a blowpipe.
They retain pores or channels in their crystal structure, easily gain or lose water, and have a high ion exchange capacity.
Zeolites are used in detergents as water softeners, and as catalysts for reforming petroleum products.
Sodium aluminosilicates, e.g. albite (NaAlSi3O8), jadeite (NaAlSi2O6), "Zeolite A", synthetic laundry detergent, Na12Al12Si12O48. 27H2O

13.3.1 Alumina as a catalyst in the cracking process
See diagram 12.1.10 : Alumina as a catalyst
Large quantities of alumina, aluminium (III) oxide, are used in the cracking processes in oil refineries.
One of the products, ethylene gas, C2H2, is used in the petrochemical industry to produce polyethylene and other polymers.
Activate alumina is very porous and is used as a filter for water treatment, an adsorption desiccant and a catalyst for natural gas and oil refining processes.
Experiment
Use a fume hood for this experiment.
Hot paraffin oil and ethylene gas are flammable.
Set up the apparatus as in diagram 12.1.10.
See diagram 12.1.10 : Alumina as a catalyst.
Put 5 cm of paraffin oil and boiling chips in the boiling tube.
Clamp it at a shallow angle, then put 0.5 g of alumina powder half way down the boiling tube, then replace the stopper.
Hheat the alumina strongly with a Bunsen burner, then heat the alumina and paraffin oil alternately until the paraffin oil boils and its vapour passes over the alumina.
Let the first few bubbles of gas escape under the fume hood, then collect two test-tubes of gas.
Fix stoppers on the test-tubes.
Immediately after collecting the two test-tubes of gas, turn off the Bunsen burner and remove the delivery tube and stopper from under the boiling tube.
This action prevents water "sucking back" into the boiling tube as it cools.

13.3.2 Aluminium chloride with water
Be careful! Demonstrate this reaction only to senior students.
Place < 5 g of aluminium chloride in a beaker in a fume cupboard and add water drop-by-drop.
The material will hiss, crackle and release clouds of hydrogen chloride and fine particles.
Anhydrous aluminium chloride, AlCl3, reacts violently with water to form the hydrated salt by hydrolysis, and a solution of hydrochloric acid + HCl gas.
Formation of an acid solution is more like a non-metal than a metal, which reflects the position of aluminium to the right of magnesium in the periodic table.
Fine aerosol particles may also be generated.
Both the hydrogen chloride gas and the fine particles are extremely irritant to the lungs.
Aluminium chloride should only be used in a fume cupboard and only in small amounts.
Do not mix aluminium chloride with alkaline materials, e.g. sodium hydroxide, because a violent reaction may occur.
Aluminium chloride is exceedingly hygroscopic so keep it in a tightly-sealed plastic container.
Purchase the material only in small amounts, e.g. 100 g.
Aluminium bromide, AlBr3, has dangerous properties similar to anhydrous aluminium chloride.
AlCl3 (s) + 3H2O (l) --> Al(OH)3 (s) + 3H+ (aq) + 3Cl- (aq)

13.3.3 Aluminium sulfate reactions
1. Add ammonia solution, NH3 (aq) ("ammonium hydroxide") to aluminium sulfate solution.
Note the white precipitate of aluminium hydroxide that is insoluble in excess ammonia solution.
Al3+ + 3OH- --> Al(OH)3 (s)
2. Add drops of sodium hydroxide to aluminium sulfate solution.
Note the white precipitate that dissolves in excess sodium hydroxide to form sodium aluminate.
Aluminium hydroxide is amphoteric.
Al(OH)3 + OH- --> AlO2- + 2H2O
3. Add blue litmus solution to aluminium sulfate solution.
The blue litmus turns red.
Add sodium carbonate solution and note the production of carbon dioxide.
Aluminium salts in solution can act as acids, because of hydrolysis.
Al3+ + 3H2O --> Al(OH)3 + 3H +
4. Pass hydrogen sulfide through aluminium sulfate solution to produce the hydroxide, not the sulfide.
5. Mix aluminium sulfate with twice its volume of anhydrous sodium carbonate and heat it on a charcoal block.
Note the white infusible mass.
Add cobalt nitrate solution and heat again.
A bright blue solid forms.

13.3.4 Aluminium with acids
The reaction is very slow to start because ot the coating of aluminium oxide on aluminium.
After the acid has broken through the aluminium oxide, the reaction is fast, very fast if using powdered aluminium.
Dissolve aluminium in heated dilute hydrochloric acid and note that hydrogen gas forms.
2Al + 6H + --> 2A13+ + 3H2 (g).
2Al + 3H2SO4 --> Al2(SO4)3 + 3H2 Hot concentrated sulfuric acid will attack aluminium with the production of sulfur dioxide.
Dilute or concentrated nitric acid acts only very slowly on aluminium, because of passivation.

13.3.5 Aluminium with sodium hydroxide
Use aluminium cooking foil or aluminium pie pans.
Use caustic soda drain cleaner from a hardware shop.
Wear safety goggles, gloves, lab coat.
Keep away any matches, sparks, flames.
If exploding hydrogen, wear ear protection.
Be careful! Hydrogen gas forms from the very rapid reaction.
1. Use a dropper to put drops of concentrated sodium hydroxide solution onto a sheet of aluminium foil or aluminium powder in a test-tube.
2. Add 5 g coarse aluminium powder to 20 ml of 40 % sodium hydroxide solution in a test-tube.
Quickly place the test-tube in the bottom of a tall glass beaker before the violent react occurs.
The coarse aluminium powder has a surface layer of aluminium oxide, which is first dissolved by the sodium hydroxide before the main reaction .
The aluminium completely dissolves and the water acts here too as an acid.
(The aluminate ion in an anhydrous compound is shown as (AlO2-), and in the hydrated form is shown as Al(OH)4-.
2Al (s) + 2NaOH (aq) + 2H2O (l) --> 2NaAlO2 (aq) + 3H2 (g) + energy.
2Al + 2OH- + 2H2O --> 2AlO2- + 3H2 (g)
2Al (s) + 2NaOH (aq) + 6H2O --> 2Na+ (aq) + 2Al(OH)4-+ 3H2 (g)
The aluminium reacts with water to form the amphoteric aluminium hydroxide, Al(OH)3, which later goes in solution to produce aluminates, (Al(OH)4)-.
2Al + 6H2O --> 2Al(OH)3 + 3H2
Al(OH)3 + NaOH --> Na+ + Al(OH)4-
Al2O3 + 2NaOH + 3H2O --> 2Na+ + 2Al(OH)4-
It is sold as "drain cleaners", e.g. Drano, contains sodium hydroxide crystals and pieces of aluminium, which react when put in a wet clogged drain.
The reaction is very hot as the sodium hydroxide reacts with fats to form soaps.
The hydrogen evolved applies pressure to move the pieces of aluminium to whirl around and cut the blockage.
3. Stand a clear glass bottle in a container of water.
Do not use a plastic drink bottle!
Add water to the bottle to 1/3 volume and add water to the container so the water levels in the bottle and container are the same.
Add a small measured amount of caustic soda to the bottle.
Pick up the bottle, dissolve the caustic soda by swirling the bottle, then replace the bottle in the container.
Roll a sheet of aluminium foil into a tube to fit through the mouth of the bottle.
Attach a balloon to the mouth of the bottle so that it fills with hydrogen gas.
Attach a balloon clip and let the balloon float up in the air.
If the balloon does not float up in the air, because it is not full enough, wait until the bottle has cooled and repeat with more caustic soda and aluminium foil.
If the balloon does not float up in the air and feels heavy, the reaction has been too vigorous so some water has condensed in the balloon.
So wait until the bottle has cooled and repeat the experiment with>less caustic soda and aluminium foil.

13.3.6 Aluminium with sulfur
Mix dry aluminium powder with twice its volume of sulfur powder.
Put into a test-tube only enough to cover the bottom of the test-tube.
Be careful! Larger quantities may explode! Set up a safety screen.
Clamp the test-tube vertically and heat with a Bunsen burner.
Note the vigorous action where aluminium sulfide is synthesized.
Leave to cool, then add drops of water.
Hydrogen sulfide forms, because of the hydrolysis of the aluminium sulfide.
2Al + 3S --> Al2S3
Al2S3+ 6 H2O --> 2Al(OH)3 (s) + 3H2S (g)

13.3.7 Bauxite digestion
Wear safety gloves and safety spectacles.
Weigh 10 g of ground, dried bauxite and transfer to a reflux flask.
Add 100 mL of 20% sodium hydroxide solution and boil under reflux for 1-2 hours.
Leave to cool, then transfer the solution and residue to a 200 mL volumetric flask.
To make sure all the contents of the reflux are transferred, use demineralized water.
Leave to cool, then make up to volume with demineralized water.
When the muddy residue has settled overnight, remove a 10 mL aliquot to a 250 mL beaker and dilute to 100 mL with demineralized water.
Heat the mixture until it boils, then make acid with 1: 1 HCl using methyl red indicator.
Add 2 g of ammonium chloride, then add 1: 1 ammonium hydroxide until the yellow end point is reached.
Boil the mixture to coagulate the precipitate, then filter it while still hot and wash the precipitate on the filter paper with hot water.
Leave the precipitate and filter paper overnight to dry to a slightly damp consistency.
Transfer the precipitate to a weighed crucible, e.g. porcelain, silica or platinum.
Dry the precipitate on the edge of a hot plate.
Do not allow any material to be lost by spitting.
Transfer the crucible and contents to a muffle furnace and ignite to a constant weight at 1, 0000 oC to 1, 200 oC.
Leave the crucible and contents to cool in a desiccator, then weigh them.
Calculate the percentage of alumina in the the bauxite: (weight of crucible and residue - weight of crucible) × 20 × 100 / weight of the sample.
If the "mud" is left with the solution it contributes to less than 1% of the total volume, an almost insignificant error.
The alumina content can also be determined volumetrically with EDTA.

13.3.8 Burn aluminium in oxygen
Sprinkle aluminium powder onto a Bunsen burner flame or heat aluminium powder in a crucible, then lower it into a gas jar of oxygen.
The aluminium burns brightly to form the white powder magnesium oxide.
4Al (s) + 3O2 (g) --> 2Al2O3 (s)
aluminium + oxygen --> aluminium oxide
Aluminium oxide is an amphoteric oxide that does not dissolve in water.
Stored aluminium is always coated with aluminium oxide, which protects it from most chemical reactions.
So aluminium can be used for many purposes where an unreacted metal is needed.

13.3.9 Corrosion of aluminium
Put a piece of aluminium foil in water.
Put a copper coin on the foil and leave it for some days. A simple aluminium /copper cell forms and a small electric current can be detected with an ammeter.
The aluminium foil has holes where the coin lies on it.
The water appears cloudy, because of the fine particles of aluminium released during corrosion.

13.3.10 Heat aluminium foil
Heat aluminium foil to form aluminium oxide
Aluminium foil (al-foil, alu-foil, "Reynolds wrap'), has thickness usually < 0.2 mm.
It is shiny on one side and matte on the other side, caused by the rolling process of manufacture.
Heat a piece of aluminium cooking foil or a "silver" milk bottle top.
Describe what happens to the aluminium foil.
You may not see any changes, because aluminium does not change colour when heated.
The melting point is 655 oC to 660 oC.
When white hot, it slowly forms a coating of aluminium oxide, alumina.
Do not heat aluminium powder.
If not pure, it may explode.
4Al (s) +3O2 (g) --> 2Al2O3 (s)
aluminium + oxygen --> aluminium oxide.

13.3.11 Iodine with aluminium
Use < 5 g total material of iodine to react with aluminium powder in a fume cupboard.
However, be aware that a cloud of unreacted iodine vapour may be released.
Fine particles of aluminium react violently with iodine, especially after a drop of water has been added.
A large amount of unreacted iodine is liberated as purple vapour into the air.
This reaction should only be done with < 5 g of materials and in a fume cupboard or outdoors.
Mix the ingredients in a small ceramic mortar and pestle.
All observers must wear eye protection.

13.3.12 Tests for aluminium
1. Heat charcoal with fusion mixture, note heated metal appearance.
Aluminium produces a white residue.
Add drops of cobalt nitrate solution and heat again to form a blue mass, but this is also caused by fusible phosphates, arsenates, borates and silicates.
2. Test aluminium
Test aluminium after dipping it in concentrated hydrochloric acid then press it on absorbent paper to remove the layer of aluminium oxide.
The voltage reading will start at a low value then increase as remaining aluminium oxide dissolves.
Record the maximum value.

13.3.13 Tests for aluminium compounds
Put two drops of red cobalt chloride solution on to a piece of filter paper.
Add two drops of aluminium sulfate solution.
Dry the paper by holding it over a flame and then ignite it over a saucer.
The ash is blue.
This is a test for all aluminium compounds in solution.

13.3.14 Tests for aluminium compounds in solution
Put 2 drops of cobalt chloride solution (red) on a piece of filter paper.
The drop 2 drops of aluminium sulfite solution of the filter paper.
Hold the filter paper over a small flame, then ignite it over a saucer.
A blue ash indicates aluminium compounds.

13.3.15 Thermite reaction
Be careful! The thermite reaction is a hazardous experiment.
Mix aluminium powder or aluminium turnings with iron oxide and ignite the mixture with a burning magnesium ribbon.
Do the experiment in the open with observers at least ten metres away.
Do not use > 25 g of the reaction mixture.
Make the reaction mixture in a cut down aluminium beverage can, suspended above a bucket or trough of sand to contain the molten iron formed.
The mixture may be difficult to ignite, but burns with white heat, producing molten iron that can be tapped from the bottom of the container.
Be careful! Burning magnesium ribbon held close to the eyes may cause eye damage.
The mixture may react violently if the aluminium particles are too fine.
Any trace of moisture in the reactants or container may cause violent evolution of steam and ejection of the white hot contents.
2Al + Fe2O3 --> 2Fe + Al2O3
8Al + 3Fe3O4 --> 9Fe + 4Al2O3
Thermit welding is used to weld iron rails together.
2Al + 3FeO -->3Fe + Al2O3
2Al + Fe2O3 --> 2Fe + Al2O3
The ends of the rails are encased in thermit putty to hold the molten products of the reaction.
The putty consists of silica sand, bentonite, carboxymethyl cellulose and water.

13.4.0 Aluminium powder
Aluminium powder is not safe for school use, so it is not supplied as powder.
So to avoid explosive reactions, do not grind aluminium metal to powder.
Finely divided aluminium particles (powder or fine turnings) burn in air with an intense white flame if ignited.
A significant amount of ultraviolet radiation is emitted, and the flame should not be watched with the naked eye.
Unoxidized aluminium powder reacts vigorously with both concentrated acids or alkalis to yield hydrogen gas, which is explosive when mixed with air.
The reaction may occur with such vigour that the aluminium particles and acid or alkali may be ejected from the container.
Aluminium metal reacts violently with halogens (chlorine, bromine, iodine).
The reaction of aluminium with liquid bromine is hazardous and should not be attempted.