School Science Lessons
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Chemistry H
Histamine, C5H9N3
Hordenine, C10H15NO
Table of Contents
Haber process, Prepare ammonia: 3.33.01
See: Haber Proces (Commercial)
Haemagglutinins, Lectins: 16.3.17
Haematite, Fe2O3, 35.20.20
Haeme, heme
Haemoglobin, Tests for haemoglobin, Hematrace test: 9.184
Hafnium, Hf
Halides, Tests for halides, Cl-, Br-, I-,
Halite, NaCl, rock salt, 35.20.19
Halloysite, Al4Si4(OH)8O10.4H2O, clay mineral, Dragonite, used in plastics, flame retardants, paints
Hallucinogenic drugs, hallucinogens: 11.11.9
Haloalkanes (alkyl halides), Addition reactions: 16.1.01
Haloalkanes (alkyl halides), Substitution reactions: 16.1.02
See: Halogens Elements, Compounds, (Commercial)
Halon-1211, bromochlorodifluoromethane (CBrClF2): Table, RODP
Halon-1301, bromotrifluoromethane (CBrF3): Table, RODP
Hand warmers, Iron powder heat pack:14.1.12
Handling and transferring chemicals: 3.4.10
Hands-on science activities: 2.0
Hanksite, Odour and taste: 35.15 (See 5.)
Hardite, case-hardening material containing arsenic
HARM: some health risk if absorbed
Harmaline, C13H14N2O
Harmful, Hazards: 15.1.0
Harmful substances: 15.2.3
Harmine, C13H12N2O
Harris modified haematoxylin, Prepare: 3.13.3
Hartshorn (deer's antlers)
Hassium, Hs
Haupt's adhesive, Prepare: 2.2
Hazards, hazardous substances: 15.0
HDPE, Plastics recycling code: 3.5.3
Heat (Physics)
See: Heat (Commercial)
Heat of (reaction, enthalpy, calorimeter) (Chemistry)
Heat up (apply heat to something) (Chemistry)
Heat, Tests for heat
Heavy metals
hectopascal, Pressure definitions: 12.1.01
Heelball (wax)
Heidenhain iron haematoxylin, Prepare: 3.13.5
Helium, He
Helmets, Safety helmet
Hematine, Artificial magnets, ferrite magnets: 29.4.72
Heme, haeme, haemoglobin
Hemicellulose, Cellulose (tests for wood):
Hemiterpenes (one isoprene unit) (C5H8):
Hemiterpenoids, C5:
Heparin, C26H41NO34S4
Heptachlor, C10H5Cl7, pesticide:16.4.01
Heptane, C7H16
Heptanoic acid, CH3(CH2)5COOH, enanthic acid, oenanthic acid
Heptanone, C7H14O
Herbacetin, C15H10O7
Herbal remedies, Solutions for herbal remedies: 5.04
Herbal tinctures: 3.6.0
Herbicides, weedicides: 16.7.0
Herbs: 3.0
Heroin, C21H23NO5 (abuse of volatile substances): 11.11.15
Hesperidin, C28H34O15
Hess's law: 14.07
Heterocyclic compounds: See diagram
Hex-1-ene, C6H12, 1-hexene, olefin, used tomake polyethene, Toxic by all routes, highly flammable
Hexose sugars
Hexyl bromide, C6H13Br, Bromohexane: 12.18.8
HFCS, Invert sugar, C12H24O12:
High risk substances, uncertain or unpredictable risk levels
High toxicity chemicals: 15.6.0
Highly toxic substances:
Hinokitiol, C10H12O2, monoterpene
Histamine, C5H9N3
Histamine, Antihistamines: 11.11.5
Histamine, Five member heterocycles:
Histidine, C6H9N3O2, (Table of amino acids)
Histidine DNA codons
Hofmann voltameter, Electrolysis of water: 15.5.4
Holmium, Ho
Home, Household, home, kitchen items
Honey, honeybee
Holmium, Ho
Honokiol, C18H18O2
Hooke's Law, elastic limit, stress and strain:
Hordenine, C10H15NO
Horneblende: 35.17.0 (Geology)
Hot ice, Frozen carbon dioxide ("dry ice", "hot ice" "cardice"): 3.34.5
Hotplates, Stirrers, magnetic stirrers: 1.38
See: Hotplates (Commercial)
Household, home, kitchen items
HPLC, High-performance liquid chromatography
Humectants, bulking agents, food additives: 19.4.20
Humectants, food additives: 19.4.7
Humic acid, C187H186O89N9S1, (average chemical formula), similar to fulvic acid
Humulene, C15H24, alpha caryophyllene
Huperzine A, C15H18N2O
Hyalite, SiO2.H2O, silicon dioxide, glassy opal
Hyaluronan, hyaluronic acid (C14H21NO11)n
Hydrastine, C21H21NO6
Hydrates, Decomposition of hydrates, hydrous salts: 3.30.8
Hydraulic fluid
Hydrazine, N2H4
Hydrides, List of hydrides: 1.15
Hydriodic acid, HI
Hydrobromic acid, HBr
Hydrocarbyl groups, univalent groups, hydrogen atom removed from a hydrocarbon, ethyl, phenyl
Hydrochloric acid, HCl
Hydrocolloids, Viscosity of non-Newtonian fluids:
Hydrocyanic acid, HCN, hydrogen cyanide
Hydrofluoric acid, HF:
Hydrogen, H2: 3.41.0
See: Hydrogen Elements, Compounds, (Commercial)
Hydrogen bonds, Liquids with low viscosity: 3.2.1
Hydrogen bromide, HBr
Hydrogen carbonate, HCO3-
Hydrogen chloride, HCl: 3.42.0
Hydrogen cyanide, HCN
Hydrogen fluoride, HF, hydrofluoricacid
Hydrogen iodide, Prepare HI:
Hydrogen peroxide, H2O2
Hydrogen sulfate ion (HSO4-), Sulfuric acid, ionization of hydrogen sulfate ion:
Hydrogen sulfide, H2S: 3.43.0
Hydroiodic acid (hydriodic acid) (HI), Strong acids and weak acids, Ka, pKa:
Hydrolysis of:
Hydronium ion, H3O+, hydroxonium ion, oxonium ion
Hydrophilic / hydrophobic
Hydroponics, soil-less culture solutions: 9.9.18
Hydroquinone, juglone, Quinones:
Hydrous ointment, oily cream, greasy moisturizer, wool alcohols, lanolin, phenoxyethanol preservative
Hydrous salts, Water of crystallization: 3.2.0
Hydroxonium ion, H3O+, hydroxonium ion, oxonium ion
beta-Hydroxyamphetamine, C9H13NO
Hydroxyapatite, Ca5[OH(PO4)3]
Hydroxybenzoic acids:
Hydroxybutanoic acid, C4H60O5, Malic acid
Hydroxycinnamic acids:
Hydroxygeraniol, C10H18O2, monoterpene
Hydroxyl group -OH functional group (sodium hydroxide, Na+ + OH-)
Hydroxyl ions, Tests for hydroxyl ions (hydroxide ions), ammonia solution: 13.6.5
Hydroxylamine hydrochloride, NH2OH.HCl, hydroxylammoniumchloride, Toxic if ingested, skin irritant
Hydroxypropionic acid, C3H6O3, lactic acid
Hydrozincite, Zn[(OH)3CO3], zinc bloom
Hygrine, C8H15NO
Hygroscopic, deliquescent and efflorescent substances
Hyoscine, C17H21NO4, Scopolamine
Hyoscyamine, C17H23NO3
Hypaconitine, C33H45NO10
"Hyperactive", Food allergies and intolerances: 19.2.0
Hyperforin, C35H52O4.C12H23N
Hypericin, C30H16O8
Hypnotics, Benzodiazepines:
Hypo, Na2S2O3.5H2O, sodium thiosulfate
Hypochlorite ion: ClO-, Chromium (III) hypochlorite
Hypobromous acid, HBrO, Bromine products: 18.7.19
Hypochlorite, ClO-
Hypochlorous acid, HOCl: 18.7.3 (swimming pools).

Hematoxylin, Haematoxylin
Haematoxylin (Haematein, hematein, C16H14O6)
Haematoxylon campeachianum, haematoxylum, logwood, from Brazil is wood is source of haematoxylin dye, Fabaceae
Haematoxylon is a counterstain with eosin.
Prepare haematoxylin, solution: 3.13.0
Prepare Delafield's haematoxylin solution: 3.13.1
Prepare Ehrlich's haematoxylinsolution: 3.13.2
Prepare Harris modified haematoxylin solution: 3.13.3
Prepare Mayer's haematoxylin solution
Prepare Heidenhain iron haematoxylin solution: 3.13.5
Prepare Weigert's iron haematoxylin solution: 3.13.6

Haeme, heme
Haeme, heme, haemoglobin
Carbon monoxide, properties: 3.39.0
Danger of vehicle exhausts, tailpipe gases: 18.6.3
Glycosylated haemoglobin: 8.0
Haeme, Tetrapyrroles, bilin, bilirubin, biliverdin:
Haeme A, C49H56O6N4Fe, blood: 9.214
Hematrace test for human haemoglobin: 9.184
Luminol tests for blood, Cu, Fe, Cn-: 14.3.1
Porphyrins, porphine:
The "quaternary proteins" have four joined tertiary proteins, e.g. haemoglobin The "transition metals" form complex ions and often have
catalytic activity, e.g. Fe in the complex haemoglobin molecule TMB test for blood: 9.183.

Green hair and faded hair, swimming pool:
Hair hygrometer: 37.6.0
Hair products (cosmetics): 19.7.3
Hair straightening treatments, Permanent wave, permanent crease solution
Hydrogen peroxide on hair:
Skin and hair (Primary): 2.19.

Keratin is a fibrous protein occurring in hair, wool, feathers, hooves and horns, imbedded in a matrix that makes them strong and
The proteins contain sulfur and are held together by disulfide bonds.

Hafnium, Hf
, Hf (Latin Hafnia, former name of Copenhagen), transition metal, abundant, space science heat resistance, in zirconium
minerals, in filaments for electron emission
Hafnium boride, B2Hf
Hafnium (IV) n-butoxide, C16H36HfO4
Hafnium (IV) carbide, CHf
Hafnium (IV) oxide, HFO2, in computer transistors, smartphones
Hafnium (IV) sulfate, HfS2O8
Hafnium (IV) trifluoromethanesulfonate hydrate, C4F12HfS4O12.xH2O.

1. Hard substances
To "harden" cement is to let it become "rock hard".
35.10 Mohs' scale of hardness (Geology)
Hooke's law: When a big stress results in a small strain, the material is "hard". Hooke's Law, elastic limit, stress and strain
Case-hardening (of steel)
Tests for hardness of lead, tin, and tin alloys: 3.62

2. Hardness of water
See: Water testing Hardness, (Commercial)
12.13.0 Hardness in water, water hardness, soft water
18.7.46 Magnesium hardness, (Swimming pools)
18.7.16 Total dissolved solids, (TDS), water hardness, scale
Tests for hard water to form a lather: 12.13.5
Tests for hardness in water in different water samples: 12.13.4
Tests for hardness in water using standard soap solution: 12.13.10

Hassium, Hs
, Hs (Hassia, laboratory at Hesse, Germany), radioactive transuranic element.

Health salts, Effervescent tablets, sodium bicarbonate (baking soda): 12.1.1
Health effects of chemicals: 3.0
Health risk = Food additives that may cause medical conditions
Health hazards, Draft Australian criteria: 5.0.0
Prepare fruit salts, health salts: 16.7.13.

Heat of
Heat of, enthalpy, calorimeter, Calorific value: 4.38
Calorimeters, Specific heat capacity: 22.5.0
Chemical potential energy, enthalpy:
Energy of reactions, enthalpy, Hess's law: 14.01
Exothermic reactions, give out heat energy: 14.1.0
Heat energy from chemical reactions: 3.12.0
Heat of combustion, bomb calorimeter: 22.5.7
Heat of displacement, zinc with copper sulfate: 14.1.6
Heat of fusion, crystallization, sodium sulfate: 24.1.9
Heat of neutralization with a calorimeter: 14.1.5
Heat of neutralization titration: 12.8.6
Heat of neutralization reactions, hydrochloric acid with sodium hydroxide: 3.82
Heat of reaction: 14.06
Heat of reaction, metals displace copper: 3.83
Heat of reaction, KMnO4 with glycerol: 14.1.7
Heat of rusting, steel wool: 14.1.4
Heat of solution, NaOH, KOH, NH4Cl: 3.17
Heat of solution of anhydrous CuSO4: 14.1.1
Heat pack, Sodium acetate heat pack: 14.1.11.

Tests for heat
Tests for heat, heat-sensitive paper, cobalt (II) chloride: 5.3.10
Tests for heat of reaction, chromium (VI) oxide with ethanol: 14.1.9
Tests for heat of reaction, potassium permanganate with ethanol: 14.1.8
Tests for heat of reaction, potassium permanganate with glycerol:14.1.7
Tests for heat of reaction, potassium with diethyl ether: 14.1.10.

Heat up, apply heat to something
Burners, (Commercial)
Hotplates, (Commercial)
Collect gaseous products of burning candle: 3.29
Elements combine with oxygen gas in air: 8.2.0
Endothermic reactions, take in heat energy: 14.2.0
Fire safety: 3.5.0
Heat and temperature: 4.37
Heat baking soda, decomposition:12.1.17
Heat carbonates, Prepare carbon dioxide: 13.7.6
Heat citric acid to form carbon: 12.6.2
Heat copper with iodine:
Heat different foods: 9.128
Heat different substances (Primary): 2.21
Heat dinitrogen tetroxide:
Heat fats:
Heat food with copper (II) oxide: 16.9.2
Heat glucose to form carbon: 12.7.1
Heat glycerine with sugar to form carbon: 12.7.7
Heat hydrated iron chlorides: 12.8.13
Heat hydrogen bromide:
Heat hydrogen carbonates, Prepare CO2: 13.7.7
Heat iron with iodine:
Heat iron with sulfur, synthesis reaction:
Heat nitrogen tetroxide, N2O4:
Heat sodium bicarbonate: 12.1.17
Heat sodium carbonate to form anhydrous sodium carbonate: 12.1.24
Heat sodium thiosulfate: 12.1.39
Heat sources: 8.1.0
Heat starch to form carbon: 12.7.12
Heat substances, Loss of: 11.3.4
Heat substances, decompose, may reform: 8.4.0
Heat sulfur to form sulfur dioxide: 8.2.15
Heat treatment, steel needles: 3.64
Heated air expands, balloon and glass tube,
Hot ice, dry ice, frozen carbon dioxide: 3.34.5
Ignition temperature: 8.6.1
Oven temperatures: 6.14.0
Solubility of different salts and temperature: 7.7.5
Spirit burner, alcohol lamp: 8.1.2
Substances decompose when heated: 3.30
Substances gain mass when heated, copper foil: 3.28
Substances gain mass when heated, Mg: 3.28.1
Temperature and rate of a reaction: 3.93
Tests for heat, heat-sensitive paper, cobalt (II) chloride: 5.3.10
Tests for thermal decomposition: 3.30.01.

Heavy metals
Heavy metals and "Chemical safety in schools":: 7.9.31
Heavy metals safety:
Heavy metals recycling:
Heavy metals: 2.7.0 (Table of elements)
List of heavy metal compounds: 1.14.

See: Helium Elements, Compounds, (Commercial)
See: Balloons, helium chart, (Commercial)
Helium Table of Elements
Helium properties:
Balloon sound lens, acoustic lens: 26.7.3
Balloon electroscope: 31.3.6
Critical point, critical temperature: 24.1.05
Density of gases, Helium (Table)
Packaging gases, propellants: 19.4.22
Helium balloon in a motor vehicle:

Helium, He (Greek Helios sun, emission line in sun spectrum), colourless, odourless, lightest noble gas, low cost, from party supplies
shops (helium balloons).
Helium is a non-metal noble gas (inert gas) at room temperature andpressure.
Helium has no known compounds.
Helium has separate small molecules, 0.0005% of the air, superfluidat 2.2 K, lowest boiling point, obtained from natural gas wells,
using in diving gases, balloons (in party balloons, but these balloons may travel over the oceans to fall and choke sea animals), welding.
Large concentration of helium can asphyxiate, change of pitch of voice due to increased velocity of sound.
Helium has the lowest critical temperature, -268oC Packaging gas, propellant gas E939, vapour density 0.14 compared to air.
Atomic number: 2, Relative atomic mass: 4.00260, r.d. 0.147(4 K), m.p. = -270oC, b.p. = -269oC,
Specific heat capacity: 5.19 × 103 J kg-1 K-1.

Heparin, C26H41NO34S4, sulfated glycosaminoglycan, injectable anticoagulant.
Heparin sulfate is a glycosaminoglycan covalently attached to core proteins to form proteoglycans.
It is produced primarily by mast cells in connective tissue and basiphils.
Enoxaparin, C26H40N2O36S5, low molecular weight injectable heparin, Xaparin.

Heptane, C7H16
Heptane (C7H16), n-heptane, heptane fraction, Toxic by all routes, Highly flammable:
Heptane may be used as an alternative to hexane Heptane, octane number: See diagram 16.1.1h.

Heptanone, C7H14O, CH3CH2CO(CH2)3CH3, ethyl butyl ketone, butyl ethyl ketone, methyl amyl ketone, 3-heptanone, colourless,
flammable liquid, mild banana-like fruity odour, slightly solublein water, soluble in organic solvents, used as solvent, ingredient in
fragrances, Irritant, metabolite of n-heptane, floats on water, synthetic flavouring, in perfumes, in Spearmint.

Hexachlorobenzene, Lindane: 16.3.3
Hexachloroplatinic acid, H2PtCl6.6H2O
Hexadecan-1-ol, Melting point of substances, cetyl alcohol:
Hexadecanoic acid, CH3(CH2)14CO2H, palmitic acid, saturated fatty acid, palm oil, palm kernel oil, coconut oil, animals and plants
Hexahydrobenzene, C6H12, cyclohexane, hexahydrobenzene, colourless liquid, ethereal odour, Toxic, Highly flammable
Hexahydrophenol, C6H11OH, cyclohexanol, cyclohexyl alcohol, hexahydrobenzene, hexalin, Toxic
Hexahydrothymol, C10H20O, menthol
Hexamethyl diisocyanate, OCN(CH2)6NCO, HMDI, 1, 6-diisocyanatohexane, polyurethane adhesive or surface coating, irritant
Hexanal, C6H12O, hexaldehyde (used to prepare fruity flavours)
Hexane-1, 6-diamine, (1, 6-diaminohexane) (NH2.[CH2]6.NH2)
Hexane-1, 6-diamine, Prepare nylon polymer: 3.4.7
Hexane, C6H14, CH3(CH2)4CH3, n-hexane
Hexanedioicacid, (CH2)4(COOH)2, adipic acid
Hexanedioyl dichloride, C6H8Cl2O2, adipoyl chloride, adipoyl dichloride, Toxic by all routes
Hexanoic acid, CH3(CH2)4COOH, caproic acid, acid C6 (in goat fat)
Hexanol, C6H14O, Harmful
Hexanoyl chloride, CH3(CH2)4COCl, caproyl chloride.

Hexanol, C6H14O
Hexanol, C6H14O, CH3(CH2)5OH, CH3(CH2)5OH, CH3(CH2)4CH2OH, n-hexanol, hexyl alcohol, n-hexyl alcohol, 1-hexanol,
(pharmacy preparations), Harmful, Toxic by all routes, flammable
Hexan-1-ol, Solution < 25% Not hazardous.

Hexane, C6H14
Hexane, C6H14, CH3(CH2)4CH3, n-hexane, normal hexane, hexane fraction, Toxic by all routes, Highlyflammable
Hexane, C6H14, hexyl C6H13, Stem name: hex-
Hexane, octane number: See diagram 16.1.1h
Hexane, Solution < 5%, Not hazardous
Hexane, Cleaning agents, solvents: 2.20.4
Adipic acid (hexanedioic acid)
Alkanes (CnH2n+2), paraffins (hexane):
Flammable: 7.9.22 (See 6.)
Hexane-1, 6-diamine (1, 6-Diaminohexane, NH2(CH2)6NH2, hexamethylenediamine (1, 6-hexanediamine), HMDA, hexamine,
methenamine, urotropine, ethylenediamine, store in refrigerator, strongly alkaline (use < 25 mL)
1, 6-Diaminohexane is used to make nylon polymer, hexamine fuel tablets, (heat tablets, Esbit), preservative food additive E239,
(not approved, USA, Australia), Flammable, irritant Insect repellents, (ethyl hexanediol): 16.13.8
Lactams (-NH(CO-), caprolactam:
Reactions of bromine water (bromine solution): (See: 6.)
Size of carbon atom in stearic acid molecule:
Prepare nylon polymer (1, 6-diaminohexane): 3.4.7
Tests for iodides (hexane):
Tests for unsaturated hydrocarbons:

Hexane-1, 6-diamine, (1, 6-Diaminohexane, NH2(CH2)6NH2, hexamethylenediamine (1, 6-hexanediamine), HMDA, hexamine,
methenamine, urotropine, ethylenediamine, store in refrigerator, strongly alkaline (use < 25 mL)
1, 6-Diaminohexane is used to make nylon polymer, hexamine fuel tablets, (heat tablets, Esbit), preservative food additive E239,
(not approved, USA, Australia), Flammable, irritant.

Holmium, Ho
Holmium, Ho (Latin Holmia, Stockholm), silver metal lanthanide, rare earth
Holmium chips, foil, ingot, Ho
Holmium (III) acetate hydrate, C6H9HoO6.xH2O
Holmium (III) bromide, Br3Ho
Holmium (III) chloride, Cl3Ho
Holmium (III) chloride hexahydrate, Cl3Ho.6H2O
Holmium (III) fluoride, F3Ho
Holmium (III) nitrate pentahydrate, HoN3O9.5H2O
Holmium (III) oxide nanoparticles, Ho2O3
Holmium (III) perchlorate, H2Cl3HoO13
Holmium (III) phosphate, HoO4P
Holmium (III) sulfate, Ho2O12S3
Holmium (III) trifluoromethanesulfonate, C3F9HoO9S3
Holmium wavelength calibration standard.

Honey, honeybee
See: 9.1.6
Float cork, wax and wood in different density liquids:
Rayleigh-Taylor instability: 13.4.6
Viscosity of honey: 17.4.2
Yeast population, bakers' yeast: 9.205
Use honey to condition hair and prevent split ends and frizzy hair, dress wounds and burns, with lemon soothe sore throat and relieve
coughing, substitute for cooking sugar.

Household, home, kitchen items
Beauty and skin care products: 19.7.0
Circuits in homes, ring and radial circuits:
Common measures: 3.5.4
Cooking: 19.3.0
Gels in the home kitchen:
Household fabrics: 19.5.0
Household chemicals: 19.1.0
Household chemicals checklist: 19.4.1
Household, chemicals, products, substances, kitchen hints: 19.9.0
Household fuse box, circuit breakers, Fuses, electrical fuse, fuse wire:
Household gas, laboratory gas, "lab gas"
Household power, transmission: 33.5.0
Kitchen scale, Single pan balance: 3.19
Microwaves, microwave cooking:19.3.5.

HPLC, High-performance liquid chromatography, high-pressure liquid chromatography, used to separate and identify
components in a mixture, may show concentration, e.g. [6]-Gingerol = 95% (HPLC).

Hydrazine, N2H4
Hydrazine, N2H4, diazine, Toxic by all routes
Hydrazine hydrate, NH2NH2.xH2O, hydrazine monohydrate, Toxic
Hydrazine hydrate, Solution < 1%, Not hazardous
Hydrazine hydrochloride, NH2NH2.HCl hydraziumchloride, hydrazine monohydrochloride, Toxic by all routes
Hydrazine sulfate, NH2NH2.H2SO4, hydrazium sulfate, Toxic, reacts violently with oxidizing agents.

Hydriodic acid, HI
Hydriodic acid, HI, conc. 5.5 M, solution <5 M (47%), Toxic by all routes
Hydriodic acid is pure HI in water but may be sold as 57% by mass Hydriodic acid, Solution < 1%, Not hazardous.

Hydrobromic acid, HBr
Hydrobromic acid, HBr, bromic acid, hydrobromic acid solution,
hydrogen bromide solution, 9 M (48%), Toxic by all routes
Hydrobromic acid, Solution > 2M (10%), Not hazardous.

Hydrocarbons, hydrocarbon chains, -C-C-C-, bond angle 109.5o, -CH2-CH2-CH2-
Hydrocarbon solvents, Flammable: 7.9.22, (See 6.)
Tests for gases from burning hydrocarbons: 16.4.6
Tests for unsaturated hydrocarbons:
Tests for unsaturated hydrocarbons: 16.4.8
Tests for unsaturated hydrocarbons:
See diagram 16.1.1: Alkanes, alkenes, alkynes.

Hydrochloric acid, HCl
Hydrochloric acid, HCl, 12.0.0
Hydrochloric acid, COR 1789), hydrochloric acid, 37%, spirits of salts, muriatic acid, spiritus salis
Hydrochloric acid, concentrated, 10 M, 35%, 200 mL of concentrated solution for 1 litre of 2 M solution
Hydrochloric acid, 37%, AR grade, CAS Number 7647-01-0, Molecular Weight 36.46 (1.19 g/mL, 12.08 M)
Hydrochloric acid, concentrated, > 10 M (32%), Toxic, Corrosive, lung irritant
Hydrochloric acid, < 10 M (35%) > 4 M (14%), Toxic, Corrosive, lung irritant
Hydrochloric acid, < 4 M (14%) > 0.2 M (1%), Toxic, Corrosive, lung irritant
Hydrochloric acid, < 0.2 M (1%), Not hazardous, skin irritant
Hydrochloric acid, 3 M, dilute 258 mL of 11.6 M acid to 1 litre of water, (35% hydrochloric acid)
Hydrochloric acid, 4 M, dilute 400 mL of 10 M acid to 1 litre of water
Hydrochloric acid test, effervescence, 35.13, (Geology)
Aqua regia, "royal water", dissolves gold (3 vols concentrated HCl+ 1 vol concentrated HNO3)
Copper (II) sulfate solution with concentrated hydrochloric acid, ligand substitution: 3.0
Dilute hydrochloric acid with marble chips, balloons: 17.1.4
Hydrogen chloride, HCl: 3.42.0
Dilute HCl with:
Muriatic acid
Prepare carbon dioxide: 3.34.1
Prepare chlorine:
Prepare hydrogen chloride: 3.42.0
Prepare hydrochloric acid: 3.42.01
Prepare hydrogen gas: 3.41.0
Rates of reaction
Reverse colour change, KI and HCl: 17.3.5
Sodium thiosulfate with HCl, rate of reaction: 3.92
Titrate dilute HCl with NaOH, using a burette: 8.4
Titrate dilute HCl with NaOH, using a burette, 8.4.1
Tests for substances with dilute hydrochloric acid:
Tests for hydrogen chloride:
Tests for hydrogen gas:
Tests for hydrogen peroxide: 12.12.6
Tests for hydrogen sulfide solution: 3.43.1.

Dilute HCl with:
Calcium carbonate:
Metals, acids with metals: 12.3.2
Sodium carbonate:
Acids with sodium carbonate: 12.1.25
Sodium hydroxide: 12.8.2
Sodium hydroxide, heat of neutralization:
Galvanic cell, Voltaic cell: 33.84.1.

Muriatic acid
Muriatic acid, hydrochloric acid, spirits of salt, acidum salis in hardware shops, builders for clogged drains, 37% muriatic acid (about
12 M), also use about 15%, for lowering swimming pool pH), about 30% for cleaning or etching concrete.

Rates of reaction
Concentration of reactants, HCl with Mg:
Count bubbles, dilute HCl with Zn: 17.1.1
Gas burette, dilute HCl with marble chips: 17.1.3
Magnesium with HCl:
Particle size, dilute HCl with marble chips: 17.2.1
Volume of gas, dilute HCl with Zn: 17.1.2.

Hyaluronan, hyaluronic acid (C14H21NO11)n
Hyaluronic acid, acidic, mucopolysaccharide, glycosaminoglycan, long unbranched polysaccharide, repeating disaccharide units
C14H21NO11)n, anionic, nonsulfated glycosaminoglycan in plasma membranes, wound healing
Hyaluronic acid sodium salt is obtained from from bovine vitreous humor
Poly β-glucuronic acid-β-acetylglucosamine.

Hydrogen bromide, HBr
Heat hydrogen bromide:
Prepare hydrogen bromide:
Reactions of hydrogen bromide:
Tests for substances hot conc. H2SO4:

Hydrogen carbonate, bicarbonate, -HCO3-
Bicarbonate, hydrogen carbonate, HCO3-, sodium hydrogen carbonate, bicarbonate of soda indicator solution
Decomposition, hydrogen carbonates, 3.30.2
Dilute acids with CaHCO3:
Dilute acids with NaHCO3:
Heat a hydrogen carbonate, NaHCO3:: 12.16.4
Prepare carbon dioxide, NaHCO3: 13.7.7
Tests for bicarbonates:
Thermal decomposition, bicarbonates: 3.30.2.

Hydrogen cyanide, HCN
See diagram: Hydrogen cyanide
HCN (note triple bond), hydrocyanic acid (especially as a vapour), prussic acid, Toxic, Not permitted in schools.

Hydrogen fluoride, HF
Hydrogen fluoride, HF, hydrofluoric acid, conc. 29 M, Very Toxic, Not permitted in schools
Hydrogen fluoride, Prepare HF:
Halide salts with hot conc. H2SO4:

Hydrogen peroxide, H2O2
Hydrogen peroxide concentration 30% solution is not permitted in schools.
Hydrogen peroxide as oxidizing agent: 12.12.4
Hydrogen peroxide as reducing agent: 12.12.5
Hydrogen peroxide bleaching action: 12.12.8
Hydrogen peroxide clock reaction, 17.1.8
Hydrogen peroxide concentration and storage: 3.49.2
Hydrogen peroxide decomposition:
Hydrogen peroxide oxidizes sulfur dioxide to sulfuric acid:
Hydrogen peroxide, manganese (IV) oxide: 17.1.5
Hydrogen peroxide with KI, iodine clock: 17.1.6
Hydrogen peroxide with KI, colour change: 17.3.5
Hydrogen peroxide with sodium thiosulfate:
Magnesium displaces hydrogen, acetic acid:
Molar volume of oxygen prepared with hydrogen peroxide: 13.1.6
Prepare hydrogen peroxide solution: 12.12.3
Prepare oxygen gas with hydrogen peroxide: 3.49.0
Series dilution of hydrogen peroxide: 5.4.7
12.12.3Tests for hydrogen peroxide, ionization reaction
12.12.6Tests for hydrogen peroxide.

Hydrogen peroxide, H2O2, "peroxide"
Hydrogen peroxide > 30% W/W causes painful white blisters on theskin that heal slowly
Hydrogen peroxide, 8% at a beauty supply store, for preparing "peroxide blondes"
Hydrogen peroxide, 6% W / V, 20 volume, mouthwash: 1 part + 9 partswater, irritant, disinfectant
Hydrogen peroxide, 3%, 3 g per 100 mL, mouthwash 60 mL in equal amount of water, disinfectant
Low cost: from pharmacies and drugstores, 3% (10 vols), and 6% (20 vols), hydrogen peroxide, from beautician and hairdressers
supply stores (for blonding hair), 12% (40 vols), hydrogen peroxide, from some pool supplies stores, higher concentrations ("Liquid
Hydrogen peroxide, H2O2, "peroxide", peroxide, (of hydrogen), bleach, antiseptic, wastewater treatment for BOD (biological oxygen
Contact with the eyes can cause serious long-term damage.
Corrosive solution can cause skin burns.
Decomposition may cause oxygen pressure build-up.
Tightly sealed bottles of hydrogen peroxide may explode due to a build up of pressure of oxygen gas.
Forms potentially explosive compounds with ketones (acetone), alcohols, (ethanol), esters, glycerine (glycerol), aniline, triethylamine
and sodium carbonate.
Do not mix hydrogen peroxide with powdered Mg, Zn or Al.
A 3% solution is unstable
It decomposes slowly in storage to yield water and oxygen.
It can decompose rapidly in the presence of catalysts.
It is difficult to transport because of regulations governing is transport by air, sea and land.
It is sold as a colourless solution for disinfecting and for bleaching hair, silk, and wool.
It readily parts with one of its two oxygen atoms and forms water.
These oxygen atoms cause the disinfecting and bleaching actions.
The strengths of the solutions usually sold are marked as 10 volumeand 20 volume, that refer to the volume of oxygen given by 1 cc of
the liquid.
So 20 volume means that 1 cc of the solution yields 20 cc of oxygen.
If possible buy a small bottle of 20 volume solution.
It is usually kept in dark glass bottles, because light hastens thedecomposition into water and oxygen.
Hydrogen peroxide solution, 30 % (w/w) in H2O, contains stabilizer MSDS: Harmful if swallowed.
Risk of serious damage to the eyes.
Heating may cause an explosion.
ontact with combustible material may cause fire.
Harmful by inhalation and if swallowed.
Causes severe burns.
Use hydrogen peroxide to remove blood stains.

3.49.2 Hydrogen peroxide concentration and storage
Hydrogen peroxide 50% w / w solution
Hydrogen peroxide, 100 volume, vols, 30% w / w solution
Hydrogen peroxide, 8-20%, Hydrogen peroxide, 40 volume, vols, 12%w / v solution
Hydrogen peroxide, 5-8%, Hydrogen peroxide, 20 volume, vols, 6% w/ v solution (hair and teeth bleach, antiseptic)
Hydrogen peroxide, < 5%, Hydrogen peroxide, 10 volume, vols, 3% w / v solution
Hydrogen peroxide may be sold in pharmacies in two strengths as follows:
A. 3% aqueous solution w / v, 3 g / mL, 10 volume, 10 vols (10% volume)
B. 6% aqueous solution w / v, 6 g / mL, 20 volume = 20 vols (20%volume)
The strength of an aqueous solution is represented by the volumes of oxygen that 100 cm3 of the liquid solution will give
on decomposition.
So a 20 volume concentration means that when 1 volume of hydrogenperoxide solution is decomposed, it produces 20 volumes of
As a hydrogen peroxide 20 volume solution contains 6% H2O2, 60g of H2O2 in 1000g of solution, atomic mass of H2O2 (H atomic
mass 1.008, oxygen atomic mass 16) = 34.016, so the concentrationof a 20 volume solution is 60 / 34.016 = 1.76 m.
The smaller concentration, 3% w / v H2O2, is less stable and decomposes faster at room temperatures so the actual concentration is
probably less than 3%.
Protect hydrogen peroxide solution from light and store in a coolplace.
Keep it in a brown glass bottle closed with a glass stopper, paraffined cork or plastic screw cap.
Airlines may not be allowed to carry hydrogen peroxide as freight.
Hydrogen peroxide test strips are available that contain a peroxidereagent to detect production of hydrogen peroxide by certain
bacteria, e.g. Streptococcus pneumoniae
Hydrogen peroxide is used as an antiseptic where catalase enzyme in blood catalyses the decomposition of hydrogen peroxide to
water and oxygen.

Hydrogen gas properties:
Hydrogenation, cis-trans fatty acids:
Formation of alkanes:
Trans fatty acid (trans fat), is a fatty acid formed as a result ofhydrogenation.

Hydrogenation is the addition of hydrogen to a moleculeto convert unsaturated organic molecules to saturated molecules and reducing
double bonds to single bonds.
For example: H2C=CH2 + H2 -->CH3CH3
alkene + hydrogen --> alkane
Trans fatty acid are fatty acids formed as a result of hydrogenation.

Hydrolysis of:
Ammonium chloride:
Antimony chloride, reversible reactions:
Bismuth chloride, reversible reactions:
Esters, Hydrolysis of esters: 16.5.4
Ethyl acetate, autocatalytic hydrolysis: 17.3.15
Iron (III) chloride, iron chloride: 12.10.5
Salts: 12.10.3
Sodium hydrogen carbonate:
Starch by dilute hydrochloric acid: 9.129
Starch by salivary amylase (ptyalin): 9.130
Tests for hydrolysis of starch (dilute hydrochloric acid): 9.129
Test for hydrolysis of starch, iodine test, Fehling's solution: 16.10.1
Tests for hydrolysis of starch (salivary amylase): 9.130
Tests for, hydrolysis of sucrose, by dilute acids): 9.131
Tests for hydroxides:

Hydrolysis is the splitting of molecule using a reaction with water AB + H2O --> AH + BOH
In the above equation, compound AB is decomposed and the hydrogenand hydroxyl group of water are attached to the separate
chemical products, AH and BOH.

Acids and metal hydroxides, insoluble base, prepare salts: 2.3
Alkalis and amphoteric oxides and hydroxides: 12.7.7
Alkalis with salts, hydroxides: 12.7.4
Decomposition of hydroxides: 3.30.3
Dilute acids with hydroxides, Mg(OH)2: 12.3.6
Dilute acids with hydroxides, NaOH: 12.3.7
Hydroxide (hydroxo), O-H-, monodentate ligand
Tests for ammonia, ammonium ions, "NH4OH":
Tests for hydroxides:
Tests for hydroxyl ions, ammonia solution: 13.6.5
Thermal decomposition of hydroxides: 3.30.3.

Hydronium ion, H3O+, hydroxonium ion, oxonium ion
Hydrogen bond: 3.01.3
Hydronium ion (hydroxonium ion): 7.9.32
Hydronium ion, Acid-base reactions:
Hydronium ion, Oxides and Periodic Table:

An hydronium ion H3O+ is formed when acids dissociate in water IUPAC prefers "oxonium ion", i.e. an ion with a trivalent oxygen
cation, and allows "hydroxonium ion", but "hydronium ion" seems to be the most popular way of referring to "H3O+".

Hydrophilic / hydrophobic
1. Hydrophilic substances are "water-loving" substances, polar molecule materials that mix with water, are attracted to water and may
dissolve in water to form hydrogen bonds, e.g. glucose, sugars.
They have an affinity for water and are readily absorbed or wetted by water.
Hydrophilic colloids readily form hydrosols or remain as hydrosols.

2. Hydrophobic substances are "water-hating" substances, non-polar molecule materials, often oily, that do not mix with water or repel
water, e.g. oils, proteins, greases, clays.
Hydrophobic colloids do not form or remain as hydrosols.
Soap molecules have one end polar and the other end non-polar so they can attach to oils yet dissolve in water.
The aversion to water of a person suffering from the disease rabiesis called "hydrophobia".

3. The hydrophobic force prevents the dispersion of oil in water, so to make oil and water emulsions, e.g. French salad dressing, the
components have to be shaken with the addition of stabilizing agents.
However, if all gases are removed from water by repeated freezingand thawing and pumping off all gases, the water will spontaneously
form an emulsion when mixed with oil.

Hygroscopic, deliquescent and efflorescent substances
3.0 Hygroscopic polymers
1.0 Hygroscopic substances
Deliquescent substances
2.0 Dry silica gel (SiO2), is hygroscopic
Efflorescent substances
4.0 Expose different salts to the air
5.0 Expose sodium carbonate decahydrate to theair Storing hygroscopic and deliquescent substances.

1.0 Hygroscopic substances absorb water from the air.
The hygroscopic solids absorb water without liquefaction.
Hygroscopic substances absorb water from the air under some conditions of humidity and temperature.
Hygroscopic chemicals include the following:
Anhydrous calcium chloride (CaCl2),
Ethanol ("absolute alcohol", C2H5OH),
Glycerol (glycerine, glycerin, CH2OH.CHOH.CH2OH),
Iron (II) sulfate-7-water (FeSO4.7H2O),
Concentrated nitric acid (HNO3),
Potassium carbonate (K2CO3),
Potassium chloride (KCl) (slight),
Concentrated potassium hydroxide (KOH),
Potassium iodide (KI) (slight),
Silica gel desiccant (SiO2),
Anhydrous sodium carbonate (Na2CO3),
Concentrated sodium hydroxide (NaOH),
Sodium nitrite (NaNO2),
Anhydrous sodium sulfate Na2SO4,
Concentrated sulfuric acid (H2SO4).

2.0 Dry silica gel (SiO2), is hygroscopic
It absorbs water from the air, but does not dissolve in the waterIt occurs naturally and is manufactured as beads to be used as a
desiccant in laboratory glass vacuum desiccators and in silica gel packets packed with equipment, e.g. microscopes, food products
and toilet products.
Be careful! The packets may usually bear a warnings not to eat the contents, so children should not have access to them, thinking
they are packets of lollies!

3.0 Hygroscopic polymers
"Fortune Teller Fish" (child's toy)
Hygroscopic polymers, including nylon, ABS, polycarbonate, cellulose, and Poly(methyl methacrylate).
Some forms of hygroscopic red cellophane used in novelties are flaton a warm dry surface but curl up in the hand when they absorb
sweat and evaporate moisture.

4.0 Expose different salts to the air
Put equal volumes of different salts on separate watch glasses, e.g. dry calcium chloride, copper (II) sulfate-5-water,
iron (II) sulfate-7-water, potassium carbonate, dry silica gel, pure sodium chloride, and sodium sulfate-10-water.
Examine the salts after one hour and after one day.

5.0 Expose sodium carbonate decahydrate to the air
The relative molecular mass of sodium carbonate-10-water = 286.15.
The relative molecular mass of anhydrous sodium carbonate = 105.99.
The relative molecular mass of sodium carbonate in sodium carbonatecrystals = (105.99/286.15) X 100 = 37%
Open an unopened packet of washing soda.
Put 10 g of washing soda in an evaporating basin.
Record the time for the crystals to change into a white powder.
Leave the basin for two days.
Record the time for all the crystals to change into a white powder.
Weigh the powder.
Calculate the weight of the powder expressed as the percentage of the original weight of the crystals.

Hypochlorite, ClO-
Calcium hypochlorite, Ca(OCl)2:
Checklist of daily routine for the swimming pool operator: 3.9.2
Decomposition, NaHCO3: 17.3.14
Hypochlorite: Calcium hypochlorite
Hypochlorites, hazards: 3.7.7
Inorganic hypochlorites, swimming pool:
Pass chlorine through water: 13.4.9
Prepare chlorine:
Prepare chlorine water: 13.4.2
Sodium hypochlorite
Sodium hypochlorite, swimming pools:

19.4.1 Household chemicals checklist
Abrasives, carbides
Acetic acid, vinegar
Acetone, nail polish remover
Albumen, egg white
Alcohol, ethanol
Adhesives, glue
Algicide, swimming pool cleaner
Ammonia, cloudy amonia cleaner
Alum, potassium alum
Aluminium, beveragecan, foil
Ammonium carbonate, smellingsalts
Ammonium chloride, solder flux
Ammonium sulfate, fertilizer
Antifreeze, coolant
Aspirin, ASA
Baking powder, leavening agent
Baking soda, bicarb
Bakelite, plastic
Bean curd, tofu
Bitumen, asphalt
Bleach, Ca hypochlorite
Borax, Na borate
Boric acid, boracic acid
Calcium carbonate, egg shell
Ca hydroxide, lime water
Ca hypochlorite, bleaching powder
Calcium oxide, garden lime, quicklime
Calcium sulfate, school chalk
Candles, wax
Carbon, charcoal, graphite
Carbon dioxide, expired air
Carbon tetrachloride, dry cleaning fluid
Cement, binder
Chlorine gas, swimming pool
Chromium, plating
Citric acid, lemon juice
Clay, soil mineral
Copper, wire
Cooking oil
Copper (II) sulfate, bluestone
Bordeaux mixture, fungicide
Cream of tartar
Cyanoacrylate, glue
Dry cells, torch battery
Fruit salts
Emulsions, face cream
Fat, lipids
Formic acid, ant poison
Gas-Pak, gas
Gelatine, jelly
Glass, window
Glucose, jellybean
Gluten, bread
Hydrogen peroxide, "peroxide"
Hydrochloric acid, muriatic acid
Ice, ice lolly
Ink, fingerprint
Iodine, tincture of iodine
Iron, nails
Kerosene, paraffin oil
Lead, fishing sinker
Lemon juice, citric acid
Lime, garden lime
Linseed oil
Magnesium hydroxide, magnesia
Magnesium sulfate, medicine
Methylated spirits, "metho"
Milk, icecream
Oil, lubricating oil
Oil, cooking oil
Petrol, gasoline, gas
Petrolatum, "Vaseline"
Polymers and plastics, ball pointpen
Potassium permanganate, Condys crystals
Putty, window
PVAC glue
Red Lead, paint
Silica, quartz
Silicone, sealant
Sodium bicarbonate, "carb soda"
Sodium carbonate, washing soda
Sodium chloride, table salt
Sodium hydroxide, caustic soda
Sodium metabisulfite, sterilizer
Sodium silicate, water glass
Silicon carbide
Solders, flux
Sucrose, sugar
Talc, tailor's chalk
Tin, tin can
Turpentine, turps
Water (Chemistry)
Water (Physics)
Yeast, bread