Chemistry Experiments, G¶

1. Aerosol spray adhesive, sensitive spray glue, for binding textile, fabrics, paper, cardboard, flat PVC, foils, urethane / rubber foams, cork, pictures, photograph mounting, 330 g can

2. "Bostik" kids paste, non-toxic, with brush, 250 mL bottle

3. "Bostik" clear gum, non-toxic, bonds paper and cardboard, 5 litre

4. "Bostik" kids PVA, non-toxic, non-staining dries clear easily wash off clothes, 1 kg, 5 litre bottle

5. "Clag" paste, non-toxic, easy to apply with brush applicator, for cut and paste and papier mache, dries after 10-20 minutes, 150 g, 300 g, 5 kg bottle.

6. "Clag", celmix, non-toxic adhesive powder, for finger painting, thickeningPVA, hardboard sealer, 500 g container

7. "EC Mix-a-paste", non-toxic, multipurpose adhesive powder, 500 g

8. "EC Mix-it", instant papier mache, just add water, 2 kg pack

9. "EC" Tintex craft paste, non-toxic, non-staining, cellulose powder, adhesive for papier mache or gelling base for finger paint, 500 g tin

10. PVA glue, witches hat lid, kids school glue, non-staining, non-toxic, general classroom use, 250 mL bottle

11. PVA glue, Helmar, professional woodworking glue, 5 litre bottle

12. "UHU" craft glue, PVA, non -toxic, quick setting, washable adhesive, for hobby, arts and craft, general all purpose water resistant, 33 mL

13. "UHU", WOW glue stick, Goes on Purple, coloured overlay, dries clear, safe non-toxic, acid free, washable PVP glue stick, suits young children, 36 g

Accessories

14. Double -sided tape, high tack, acid and solvent free, 6 mm wide ×50 m roll

15. Glue brushes, flat, 15 mm wide, pack / 24

16. Paste spreaders, plastic paddles, 130 mm, pack / 24

17. "Sellotape" sticky dots, removable, clear double sided pack / 64, 1600

12.1.5 Glycerine with borax solution, colour change¶

In test-tube 1, dissolve 2 mL of borax in half a test-tube of water and add two drops of phenolphthalein solution.

The liquid turns a rose red colour.

In test-tube 2 dissolve one drop of glycerine in 2 cm of water.

Add the test-tube 2 glycerine solution, drop by drop, to the test-tube 1 borax solution until the red colour disappears.

Heat test-tube 1 and the red colour reappears.

Cool test-tube 1 and the red colour disappears.

This heating and cooling effect can be repeated.

Repeat the experiment using sugar solution instead of glycerine.

12.1.6 Glycerine oxidation, Oxidation of glycerine¶

Add drops of hydrogen peroxide and a small crystal of iron (II) sulfate to 5 g of glycerine in a test-tube.

Hold the test-tube in a paper holder and heat the mixture over a flame.

A vigorous reaction occurs as the glycerine is oxidized to glyceraldehyde.

Add a blue precipitate from the reaction of copper hydroxide with copper sulfate solution and sodium hydroxide solution.

Heat the test-tube and a yellow precipitate that turns red of copper (I) oxide Cu₂O, cuprous oxide) forms. source

12.1.7 Heat glycerine with sugar to form carbon¶

Put into a dry test-tube 5 g of glycerine and an equal amount of sucrose sugar.

Heat the test-tube over a flame.

A black mass of carbon forms in the test-tube.

12.7.2 Tests for glucose and sucrose, copper hydroxide¶

Heat a glucose solution with copper hydroxide solution.

A precipitate of copper (I) oxide (Cu₂O, cuprous oxide), forms that gradually turns to red. source

This test reaction does not occur with sucrose.

12.7.3 Tests for glucose in apples and sweets¶

Cut four pea size pieces of apple and put them into a test-tube with 5 mL of sodium carbonate (washing soda), crystals.

Add 2 cm of water.

Hold the test-tube in a paper holder and heat it over a flame.

When the liquid begins to boil, continue the heating for four minutes.

A red-brown solution gradually forms that then gradually darkens until it is almost black.

Note the faint smell of burnt sugar.

This test reaction does not occur with sucrose.

Repeat the test with barley sugar and "Glucodin".

12.7.4 Tests for glycerine¶

Commercial "glycerine" is about 95% glycerol.

Glycerine, glycerin, is a product containing at least 95% glycerol, C₃H₈O₃, CH₂OH-CHOH-CH₂OH, glycerin, 1,2,3-propanetriol source

The terms glycerine, glycerin, glycerol may have no precise meaning in different countries and in different products.

Experiment

Heat drops of glycerine in a dry test-tube with powdered sodium hydrogen sulfate, (sodium bisulfate).

Acrolein, C₃H₄O, ethylene aldehyde, vapour forms with a penetrating acrid smell of burnt fat in burning cooking oil. source

Do not inhale the gases from heated glycerine!

Glycine

Glycine, C₂H₅NO₂, NH₂CH₂COOH, L-Glycine, aminoacetic acid (Gly), aminoethanoic acid, smallest and simplest amino acid source

Glycine, (Table of amino acids)

Glycine, DNA codons

Leucine, See: a1,(Experiments)

Glycine and its sodium salt (flavour enhancer) E640, Glycine max , soya bean, soybean, vegetable, [soybean oil], Fabaceae: 19.2.11

Amino acids: 16.3.6.1.0

Separate amino acids by paper chromatography: 10.2.2.5

12.7.5 Glycerine with borax solution¶

In test-tube 1, dissolve 2 mL of borax in half a test-tube of water and add two drops of phenolphthalein solution.

The liquid turns a rose red colour.

In test-tube 2 dissolve one drop of glycerine in 2 cm of water.

Add the test-tube 2 glycerine solution, drop by drop, to the test-tube 1 borax solution until the red colour disappears.

Heat test-tube 1 and the red colour reappears.

Cool test-tube 1 and the red colour disappears.

This heating and cooling effect can be repeated.

Repeat the experiment using sugar solution instead of glycerine.

13.1.0 Gases by name, Ammonia to Xenon¶

The gases listed below are gases at STP and are the gases mentioned in this website.

See: Gas, Molecular weight, Density, (Table 1)

See: Packaging gases, propellants, food additives

Acid rain, NOx

Ammonia, NH₃ source

Argon, Ar

Bromine, Br

Butane, C₄H₁₀ source

Carbon dioxide, CO₂ source

Carbon disulfide, CS₂ source

Carbon monoxide, C≡O

Chlorine Cl₂ source

Coal gas, (50% hydrogen gas)

Ethane, C₂H₆ source

Ethene, (Ethylene), C₂H₄ source

Ethyne, (Acetylene), C₂H₂ source

Fluorine, F

Helium, He

Heptane, C₇H₁₆ source

Hexane, C₆H₁₄ source

13.3.4, Hydrogen gas, H₂ source

Hydrogen bromide, HBr

13.3.2, Hydrogen chloride gas, HCl

Hydrogen fluoride, HF

Hydrogen sulfide gas, H₂S source

Krypton, Kr

Methane, NH₃ source

Neon, Ne

Nitric oxide gas, NO

Nitrogen gas, N₂ source

Nitrogen dioxide gas, NO₂ source

Nitrogen triiodide, NI₃ source

Nitrous oxide gas, N₂O source

Oxygen, O₂ source

Ozone, O₃ source

Packaging gases

Pentane, C₅H₁₂ source

Phosgene gas, COCl₂ source

Propane, C₃H₈ source

Radon, Rn

Sulfur dioxide, SO₂ source

Sulfur trioxide, SO₃ source

TrichloroethaneH, C₂H₃Cl₃ source

TrichloromethaneH, chloroform, CHCl₃ source

Xenon, Xe

13.3.0 Prepare gases with gas generation apparatus¶

See diagram 3.32ch: Gas generation apparatus

See diagram 3.33ch: Collect gas with an angle-tube syringe

Be careful! Prepare poisonous gases only in a fume hood or fume cupboard, e.g. preparation of chlorine, hydrogen chloride, sulfur dioxide.

1. See diagram 3.32ch: Gas generation apparatus, No. 1.

Collect more dense gas by upward displacement of air (downward delivery), if molecular mass > 28.8.

The more dense gas sinks down into, and displaces, the less dense air upwards, e.g. preparation of carbon dioxide, nitrogen dioxide.

2. See diagram 3.32ch: Gas generation apparatus, No. 2.

Collect less dense gas by downward displacement of air (upward delivery), if molecular mass < 28.8.

The less dense gas rises into, and displaces, the more dense air downwards, e.g. preparation of hydrogen, ammonia.

Use a borosilicate test-tube that is not cracked.

Clamp the test-tube to a stand.

Put the solid reagent in the sidearm test-tube and the liquid reagent in the reservoir.

Add the liquid reagent very slowly drop by drop.

Keep the reservoir tap closed and the reservoir full to prevent gases blowing back.

Grease the stopper and insert it so that if an accidental sudden increase in pressure occurs, the stopper blows out of the test-tube.

Use rubber tubing to collect the sidearm to a delivery tube that leads into the receiving test-tube.

Discard the first gas coming out of the delivery tube, because it is mostly air.

Never allow a flame near the gas as it comes out of the delivery tube.

Some air probably remains in the receiving test-tube.

Use the gas bubbler to collect over water insoluble gases with similar density to air.

Some water vapour remains in the receiving test-tube.

Gases can also be collected in balloons, inflatable footballs, and plastic bags.

3. See diagram 3.32ch: Gas generation apparatus, No.3

Collect insoluble gas, or not very soluble gas, of any density over water, i.e. by downward displacement of water. (water displacement), e.g. preparation of oxygen.

Fill one third of the water trough.

Fill a test-tube with water by placing it on its side in the water trough.

Put your thumb over the end of the test-tube and invert it.

Fix the end of the gas delivery tube inside or under the test-tube.

If the gas is slightly soluble in water its solubility will be less in warmer water.

Some gases dissolve in water to produce heat and form an acid solution, e.g. HCl, SO₂, NO, NO₂. source

Some gases dissolve in water to form a basic solution, e.g. NH₃. source

4. See diagram 3.32ch: Gas generation apparatus, No. 4.

Collect soluble gases in water (aqueous solution), e.g. Cl₂. source

5. See diagram 3.32ch: Gas generation apparatus, No. 5.

When the gas preparation equipment uses downward displacement of water (Diagram 3.) or collection in water (Diagram 4.), water may be forced back into the equipment by atmospheric pressure i.e. "sucked back", and break hot glassware or dilute reactants.

To prevent sucking back, use an inverted glass filter funnel.

6. See diagram 3.33ch: Collect gas angle tube syringe

Collect gas with an angle tube syringe that can collect and store gas of any density.

16.6.5 Dihydric alcohols, glycols¶

The dihydric alcohols, glycols, diols, have two hydroxyl groups on different carbon atoms, e.g.:.

1.Ethane-1,2-diol, ethylene glycol, ethanediol, "glycol", 1.2-dihydroxyethane

(C2H4O)nH2O, CH₂OHCH₂OH, BP 197.5 oC, car radiator antifreeze, coolant, in hydraulic fluids, paint and plastic solvent, sweet taste, but poisonous source

2. Butane-1,4-diol, C₄H₁₀O₂, HO(CH2]4OH, tetramethylene glycol source

CH₂CH₂ (oxidation) → CH₂OCH₂ (+ water) → HOCH₂CH₂CH₂CH₂OH source

ethene (oxidation) → epoxyethane (+ water) → ethane-1,2-diol (glycol, antifreeze) source

3. Propane-1,2 diol, propylene glycol, C₃H₈O₂, CH₃CHOHCH₂OH, colourless, tasteless, odourless, solvent for pharmaceuticals source

16.6.11 Nitrocellulose, gun cotton¶

This preparation is too dangerous to be done in schools.

Potassium nitrate is dissolved in concentrated sulfuric acid to produce a dangerous vapour, then cooled in an ice and salt mixture, then cotton balls are added.

Later more sulfuric acid is added, then the cotton balls are removed and placed in sodium bicarbonate solution until no more bubbles form, then dried.

Gunpowder, black powder: potassium nitrate + sulfur + charcoal

16.6.121 Gypenoside¶

Gypenoside XVII, C₄₈H₈₂O₁₈, a beta-D-glucoside, a disaccharide derivative, occurs Panax source

Gadolinium¶

Gadolinium, Table of the Elements

Gadolinium, RSC

Gadolinium, Gd, (Johan Gadolin , (1760-1852, Finland), chips, foil, ingot, mesh, rare earth, was identified 1880, from gadolinite.

Gadolinium is paramagnetic and it is used in magnetic recording discs and tapes, in MRI contrast agents and green phosphors.

Gadolinium (III) chloride, anhydrous, powder, beads

Galactinol¶

Galactinol, C₁₂H₂₂O₁₁, sugar alcohol, an alpha-D-galactoside, monosaccharide derivative, important for carbohydrate metabolism, was first found in sugar beet. source

It occurs in (Beta vulgaris) juice, Fagus, and in Cucumis

Galactitol¶

Galactitol, C₆H₁₄O₆, dulcitol, sugar alcohol, from metabolic breakdown product of galactose, ( lactose + lactase → glucose + galactose), slightly sweet taste, neurotoxin, hepatotoxin in galactosemia or galactose intolerance genetic disorder source

It occurs in family Celastraceae.

Gallium, Ga¶

Gallium, Table of the Elements

Gallium, RSC

Gallium, Ga (Latin Gallia France, Roman region including present day France and surrounding territory), blue-white metal, conchoidal fracture

It is used in LEDs, and is found in in bauxite and zinc ores.

The discovery of gallium in 1875 by François Lecoq de Boisbaudran, France, was possibly the first element to predict existence of the periodic table.

He also discovered Samarium, Sm, and Dysprosium, Dy.

Gallium is brittle then melts at 298K, 29.77 oC, so "joke spoons" made of Gallium dissolve in a hot cup of tea!.

Gallium arsenide, GaAs, semiconductor, is used in diodes, field effect transistors, integrated circuits, compact disc players, because it transforms electric current directly into laser light, and used for ultra-high radio frequencies, fast electronic switching, lasers (DH laser), in ink that contributes to luminescence of Euro bank notes.

Gallocatechin¶

Gallocatechin, (GC), C₁₅H₁₄O₇, bioflavonoid, flavan-3-ol, polyphenolic compound, in green tea, is a free radical scavenger. source

Gallocatechin gallate, C₂₂H₁₈O₁₁, bioflavonoid, occurs in green tea. source

Galangin¶

Galangin, C₁₅H₁₀O₅, flavonol, induces cell destruction, anti-oxidative and free radical scavenger activities. source

It occurs in (Alpinia galanga), (Alpinia officinarum), and (Heliochrysum aureonitens).

Galangin 3-methyl ether, (3-Methylgalangin), (7-Dihydroxy-3-methoxyflavone), a dihydroxyflavone

It occurs in herbs and spices, and in Galanga root.

Garbanzol¶

Garbanzol, C₁₅H₁₂O₅, trihydroxyflavanone, secondary alpha-hydroxy ketone, an antimutagen source

Geosmin¶

Geosmin, C₁₂H₂₂O, a sesquiterpenoid. bicyclic alcohol, earth smell, muddy fish smell, after rain smell, cut grass smells from Streptomyces and (Calothrix cyanobacterium). source

1. The degraded sesquiterpene geosmin, C₁₂H₂₂O, a bicyclic alcohol, causes the "earth smell" of moist soil, produced by (Streptomyces antibioticus) and (Streptomyces coelicolor). source

The "earth smell", "rain smell", noticed after rain and in wet rugby dressing rooms, causes the earthy taste of beetroot, and "off tastes" in water and wine.

Blue-green algae in water can also produce geosmin.

In Australia, when heavy rain occurs after a long period of dry weather, a bad taste, "off taste", may develop in the drinking water caused by the high concentration of geosmin washed into water supply dams.

Actinomycetes bacteria grows in damp soil, but produces survival spores during hot weather.

During the first rainfall, wind suspends the spores in the air as an aerosol causing the "after the rain smell", from | Geosmin C₁₂H₂₂O |. source

The smell occurs after breathing in tiny particles of soil containing the bacteria.

2. Another explanation for the after rain smell is that volatile chemicals in the air spaces between soil particles are washed out by the rain and become relatively concentrated just above the soil.

Some people call the earth smell "petrichor", and say that is caused by plant oils that become adsorbed to clay minerals to produce an argillaceous odour.

Some people say they can smell ozone in the smell before rain and this may be true after severe lightning from thunderstorms.

3. Geosmin causes the earthy taste of beetroot and off-flavours in wine and drinking water.

4. Geosmins are produced by blue-green algae and anaerobic bacteria when they die.

Geosmins may cause the muddy smell of fish, e.g. catfish, carp and mullet.

Geosmins break down in acid solutions, so fish is generally eaten with lemon juice.

Guaiacol¶

Guaiacol, C₇H₈O₂, 2-methoxyphenol, yellow aromatic oil, disinfectant, expectorant, dental pulp anaesthetic, induces cell proliferation source

It is used to prepare synthetic vanillin.

It occurs in wood smoke by pyrolysis of lignin, in wood creosote, and in Guaiacum

Gamboge¶

Gamboge, yellow dye, formerly for illustrations, poor light fastness, poisonous, sap of Garcinia hanburyii , Clusiaceae

Garum¶

Garum, liquamen, sauces made in ancient Greece and Roman Empire from fermented fish intestines

Gases¶

Gases (Chemistry)

#GasesH">Gases (Chemistry)

Chemical vapours and smelling chemicals: 3.4.4

Fume cupboards, fume hoods: 2.2.4

Gas or vapour inhalation, EAR, CPR: 3.4.8

Gas, Molecular weight, Density, (Table 1):

Gases, states of matter, solid (s), liquid (l), gas (g) aqueous solution (dissolved in water) (aq)

Gas, Molecular weight, Density

Gas-pak: 2.2.6

Gas bags: 13.3.1

Gas constant, R, gas equation (PV = nRT): 20.3.8

Gas discharge tubes, Cathode ray tubes: 38.8.1

Gas expansion, Charles's law: 20.2.0

Gas inhalation, vapour inhalation, EAR, CPR: 3.4.8

Gas installations and inspections: 2.2.5

Gas laws:

Gases by name, Ammonia to Xenon: 13.1.0

Hazards of gases: 3.8.0

Molecular weigh of gases

Packaging gases, propellants, food additives

Prepare gases at standard conditions: 3.32, Ammonia to wood gas

Prepare gases with gas generation apparatus: 13.3.0

Separate by heating, gases dissolved in water: 3.25

Solubility of gases: 20.3.4 Henry's law and decompression sickness, "the bends"

Standard temperature and pressure, STP, density of gases: 20.0.6

Saturation vapour pressure, SVP: 12.3.1

Saturation vapour pressure over water: 12.3.2

Tests for gases and vapours: 1.0.0

Tests for gases collected in a respirometer: 9.1.19

Tests for gases from burning hydrocarbons: 16.4.6.0

Tests for gases with hot concentrated sulfuric acid:12.11.3.6

Tests for gases, Lighted splint tests: Tests

Tests for gases with hot concentrated sulfuric acid

Volume of gas dissolved in tap water: 7.7.13.1

Gases by name¶

Bunsen burner gas: 22.1.4

Butane gas, C₄H₁₀, compounds source

16.4.1 Butane

Butane

Carbon dioxide: 16.4.2

Carbon monoxide: 16.4.3

Coal gas

16.4.4 Ethane, C₂H₆ source

16.4.5 Ethene, (ethylene), C₂H₄ source

16.4.6 Ethyne, (acetylene), C₂H₂ source

Greenhouse gases, (Experiments)

16.4.8 Hexane, C₆H₁₄ source

16.4.7 Heptane, C₇H₁₆ source

Hexene

Hydrogen

Hydrogen and hydrogen gases

Laboratory gas, piped gas, "lab gas", Household gas

LPG gas, LP-gas, liquefied petroleum gas, compressed gas, bottled gas

Methane, natural gas, safety

16.4.9 Octane, C₈H₁₈ source

16.4.10 Pentane, C₅H₁₂ source

Propane gas, C₃H₈ source

16.4.11 Propane, C₃H₈ source

Town gas

Water gas, mixture of carbon monoxide and hydrogen gas, forms when steam passes over hot coke or carbon

Producer gas, air gas, similar to water gas, formed by passing air and steam over hot carbon

Gelatin¶

Gels, gelatine, gelatin, puragel, "Aeroplane jelly"

Gelatine, E441 (if contain SO₂ may cause allergies) source

Sold as: Gelatin Type A from Porcine Skin Gelatin Type B, (testing for proteins)

Amorphous, yellow to colourless, transparent, tasteless, material, brittle when dry, from collagen protein produced by boiling animal tissues, e.g. skin and ligaments

It is used in glue, jelly crystals, e.g. puragel, photographic emulsions, adhesives

Also, gelatin dynamite and blasting gelatin, underwater explosives, containing nitroglycerine and cellulose nitrate

Hydro gels, water absorbent polymers

Use jelly to style hair and grow seeds to see root structure.

Cooked collagen changes into gelatine: 19.2.8.5

Diffusion through a colloidal gel: 9.1.5

Gels: 7.8.5

Make jelly with fresh pineapple and tinned pineapple: 19.1.13

Prepare nutrient gelatin solution: 3.18

Prepare glycerine jelly solution: 6.3

Tests for pectin in jelly and jam: 16.5.8

Germanium, Ge¶

Germanium, Table of the Elements

Germanium, RSC

Germanium, Ge (Latin Germinus Germany), grey-white metalloid, crystalline, brittle, lustrous, metalloid, discovered by Clemens Winkler, Germany, in 1886, produced from. germanium silver ore argyrodite, germanite mineral, coal, and flue dusts

Germanium and germanium oxide, GeO₂, is used in semiconductors, (the first solid state amplifier, transistors), in alloys, infrared glass, catalysts, e.g. for PET plastic, fluorescent lamp phosphors, infrared source

detectors, lenses.

Germanium (IV) chloride, GeCl₄, germanium tetrachloride, Toxic by all routes, Highly corrosive, violent reaction with water, colourless, fuming liquid acidic smell source

Germanium ethoxide

Germanium Std (ICP / DCP)

Galanthamine¶

Galanthamine, (C₁₇H₂₁NO₃), Benzazepine, Amaryllis alkaloid, oral cholinesterase inhibitor, It is used to treat Alzheimer's disease, analgesic, inhibits cholinesterase activity, herbal medicine nervous diseases, used to reverse the muscular effects of gallamine triethiodide (Flaxedil) (C₃₀H₆₀N₃O₃) and tubocurarine (C₃₇H₄₁N₂O₆⁺). source

It occurs in Galanthus, Amaryllis belladonna, Hymenocallis leucojum, Lycoris squamigera, Narcissus, Pancratium, Ungernia, and Galanthus species.

Glass¶

Borosilicate glass, Pyrex: 7.9.10

Electrical conductivity of molten glass at high temperature: 32.3.2.7

Fibre glass

Glass balls (all sizes), Glass beads (all sizes)

Glass cleaning, potassium dichromate solution:

Glass cutting, tubing, cleaning: 2.3.0

Glass knife, (ceramic impregnated with diamond dust)

Glass transition temperature (Tg), chewing gum, cotton: 3.4.0

Gutta percha polymer, natural polymer, mainly trans-1.4-polyisoprene, latex of Palaquium oblongifolium )

Glass wool: 3.6.4 (Safety)

Glasses, (Safety glasses)

Prepare coloured glass: 7.4.4, (See: 3.)

Silicon, Silica, (glass): 7.4.0

Teach manipulative skills: 3.2.4 (Safety)

Test-tubes, glassware and microscope slides: 3.6.6 (Safety)

Fibre glass¶

Fibre glass resin, epoxy resins, uncured resins, may contain isocyanate residues, strong irritants to eye nose / respiratory organs

Gentamicin¶

Gentamicin, C₂₁H₄₃N₅O₇, is an amminoglycoside, from fermentation of Micromonospora purpurea or Micromonospora echinospora source

It inhibits protein synthesis, antimicrobial against strains of Pseudomonas, Proteus, Staphylococcus, Streptococcus, however it may damage the kidneys.

Gentamicin C, aminoglycoside from Gram-negative bacteria, prevents protein synthesis, growth of mycoplasma.

Gentamicin sulfate is a broad spectrum antibiotic.

Gentisic acid¶

Gentisic acid, C₇H₆O₄, (2,5-dihydroxybenzoic acid), hydroquinonecarboxylic acid, a phenolic acid, lipoxygenase inhibitor source

It is a crystalline powder, anti-inflammatory, antirheumatic, antioxidant, antibacterial, antiviral It occurs in humans, Citrus roots and leaves, (Vitis vinifera) peels, (Helianthus tuberosus) tubers, and (Eucalyptus grandis).

Geraniol¶

Geraniol, C₁₀H₁₈O, lemonol, monoterpenoid, colourleess to pale yellow oily iquid, sweet fragrant rose odour, anticancer, it occurs in citronells, lemongrass, lavender, coriander, lemon balm, basil, Damascene rose, and chinese pepper (Lanthoxylum simulans). source

Insect repellents

Germacrenel¶

Germacrene, C₁₅H₂₄, a sesquiterpene, in the essential oil of rosemary. source

It occurs in leaves of the Mexican linaloe tree (Bursera linaloe), mitsuba (Cryptotaenia japonica), hymenocrater, (Hymenocrater yazdianus), and in purple dead-nettle, (Lamium purpureum).

Ginkgoic acid¶

Ginkgoic acid, C₂₂H₃₄O₃, ginkgolic acid, a hydroxybenzoic acid source

Ginkgolic acid inhibits HIV infection in human PBMC cells.

Glazes¶

Pottery glazes were formerly metal oxides, e.g. lead oxide and cadmium oxide, often heavy metals.

Most glazes nowadays have the metal oxide fired with silica to form sintered glass.

Glazes for school use must contain no cadmium and < 0.1% lead dry weight.

Glazes are sold as "school glazes".

Glepidotin¶

Glepidotin A, C₂₀H₁₈O₅, (8-Prenylgalangin), a trihydroxyflavone, Glepidotin A, B and C in Glycyrrhiza lepidota source

Glucan¶

Glucan, C₆H₁₀O₅)n, D-glucose monomer polysaccharide, linked by glycosidic bonds source

It is sold as:

1. Glucan from cell wall of baker's yeast, Saccharomyces cerevisiae, 2. β-D-Glucan, from barley (1,3)-β-D-glucan (BG), is a biomarker for candidiasis, 3. β-1,3-Glucan, Paramylon, from Euglena gracilis.

Some α-glucans:

Chrysolaminarin, β-1,3-glucan, in phytoplankton

Laminarin, Laminaran, β-1,3- and β-1,6-glucan, in brown algae, (Laminaria digitata), oarweed

Lichenin, β-1,3- and β-1,4-glucan, in lichen reindeer food

Pleuran, β-1,3- and β-1,6-glucan, from the oyster mushroom, (Pleurotus ostreatus)

16.7.11 Yeast, fermentation, brewing, beer

Zymosan, β-1,3-glucan, found on yeast

Glucogallin¶

Glucogallin, C₁₃H₁₆O₁₀ beta-Glucogallin, glucogallic acid, galloyl beta-D-glucose, a gallate ester, in Rumex, in Rheum, in Paeonia source

Gluconic acid¶

Carbohydrates, carbohydrate acids: 16.3.1.1

E574 Gluconic acid (anti-caking agent, sequestrant), Food additive

Oxidation of glucose, blue bottle experiment: 9.3.10

SCOBY, Symbiotic Colony Of Bacteria and Yeast: 4.3.1

Glucose¶

Glucose, C₆H₁₂O₆, "D-(+)-Glucose", dextrose, glucose syrup, grape sugar, dextrose monohydrate, d-glucose, blood sugar, glucose, anhydrous, glucose (for babies), "Glucodin" source

Glucose is called grape sugar, because of its occurrence in grapes.

In table syrup, black treacle, ripe apples and cheap sweetening material for confectionery and sweets, e.g. barley sugar.

Glucose is only half as sweet as sucrose, sugar, but is more easily digested.

It is manufactured by boiling starch with dilute sulfuric acid.

Glucose is a carbohydrate, the hydrogen and oxygen being in the same proportion as in water.

Common names: Corn syrup, "Karo" syrup

Dextrose Monohydrate

E575 Glucono δ-lactone (acidity regulator, raising agent)

E576 Sodium gluconate (Banned in some countries) (acidity regulator, sequestrant)

E578 Calcium gluconate (acidity regulator, firming agent)

E1102 Glucose oxidase (enzyme, acidity regulator)

Glucose, Monosaccharides: 16.3.1.3

Amylase (fermentation): 4.5.1

Glucose fermentation: 9.1.4

Glycaemic index (GI): 9.1.1

Heat different foods: 9.128

Hydrolysis of starch by salivary amylase (ptyalin): 9.5.4

Lactic acid: 16.2.4

Lactase: 4.5.2

Left-handed and right-handed structural forms, D-sugars and L-sugars: 16.3.1.3.1

Monosaccharides: 16.3.1.3

Non-enzymatic browning, caramelization: 119.2.3.2

Oxidation of glucose, blue bottle experiment: 9.3.10, (See: 2.)

Reducing sugars: 9.3.6

E420 Sorbitol, Sorbitol syrup, (from glucose in berries or synthesized, (artificial sweetener, bulking agent, humectant)

Split lactose from milk or whey using immobilized lactase: 4.4.4

Prepare glucose

Prepare glucose with starch: 16.7.15

Prepare glucose with sugar: 16.7.18

Prepare glucose nutrient agar solution: 9.2.31

Prepare glucose nutrient agar: 9.2.16

Prepare glucose with starch: 16.7.15

Prepare glucose with sugar: 16.7.18

Tests for glucose

Tests for glucose: 19.5.8

Tests for glucose and fructose with Fehling's reagent: 9.5.4

Tests for glucose and sucrose, copper hydroxide: 12.7.2

Tests for glucose and starch, "Testape": 9.5.2

Tests for glucose, blood glucose, glucose tolerance: 19.1.26

Tests for glucose, Clinitest tablet: 19.1.24

Tests for glucose, Clinistix strip: 19.1.25

Tests for glucose concentration, ferricyanide test: 19.1.27

Tests for glucose concentration, ferricyanide test: 19.1.26

Tests for glucose, blood glucose: 19.1.26

Tests for glucose, glucose oxidase test: 19.1.29

Tests for glucose, glycosylated haemoglobin test: 19.1.30

Tests for glucose in apples and sweets: 12.7.3

Tests for glucose, Nelson-Somogyi test: 19.1.27

Tests for glucose, Nelson-Somogyi test: 19.1.28

Tests for glucose, Tollens' test: 9.3.3

Tests for glucose, urine test: 19.1.31

Tests for glucose, urine test, Diastix strip: 19.1.33

Glue¶

Gluco-chemicals¶

Glucoalyssin, C₁₃H₂₅NO₁₀S₃, flavour component, occurs in Chinese cabbage, pak choi, turnip source

Glucoaubrietin, C₁₅H₂₁NO₁₀S₂, occurs in Tropaeolaceae source

Glucobarbarin, C₁₅H₂₁NO₁₀S₂ source

Glucoberteroin, C₁₃H₂₅NO₉S₃, flavour component, occurs in horseradish>, radish. source

Glucobrassicanapin, C₁₂H₂₁NO₉S₂, flavour component, occurs in brown mustard, horseradish, swede, turnip, sea rocket. source

Glucobrassicin, C₁₆H₂₀N₂O₉S₂, occurs in Brassica, Raphanus species, and most cruciferous plants. source

Glucocapparin, C₈H₁₅NO₉S₂, occurs in horseradish, radish, cauliflower. source

Glucocheirolin, C₁₁H₂₁NO₁₁S₃, flavour component, occurs in crucifer seeds, occurs in horseradish, cauliflower, swede, turnip. source

Glucoconringiin, C₁₁H₂₁NO₁₀S₂, occurs in Conringia species. source

Glucocleomin, C₁₂H₂₃NO₁₀S₂, occurs in Cleome. source

Glucoerucin, C₁₂H₂₃NO₉S₃, flavour component, in seed of salad rocket, occurs in Brussels sprouts. source

Glucoiberverin, C₁₁H₂₀NO₉S₃, flavour component, occurs in Chinese cabbage, cabbage, cauliflower, horseradish, radish. source

Gluconapoleiferin, C₁₂H₂₁NO₁₀S₂, occurs in Brassica. source

Glucoiberin, C₁₁H₂₁NO₁₀S₃, occurs in cabbage, broccoli, occurs in Brussels sprouts. source

Glucolepidiin, C₉H₁₇NO₉S₂, flavour component, pungent like garlic, occurs in horseradish, garden cress. source

Glucolimnanthin, C₁₅H₂₁NO₁₀S₂, volatile and pungent, occurs in Limnanthes species. source

Gluconapin, C₁₁H₁₉NO₉S₂, occurs in rapeseed, brown mustard, black mustard, horseradish, wasabi (Eutrema japonicum). source

Gluconasturtiin, C₁₅H₂₁NO₉S₂, tingles tongue, water cress aroma, occurs in watercress, white mustard, garden cress, brown mustard. source

Glucoputranjivin, C₁₀H₁₉NO₉S₂, pungent, occurs in white mustard, brown mustard, wasabi Chinese cabbage, Brussels sprouts. source

Glucoraphenin, C₁₂H₂₁NO₁₀S₃, flavour component, occurs in radish seed. source

Glucosibarin, C₁₅H₂₀KNO₁₀S₂. source

Glucosisymbrin, C₁₀H₁₉NO₁₀S₂, occurs in Moringaceae. source

Glucotropaeolin, C₁₄H₁₉NO₉S₂, Benzyl glucosinolate, occurs in Cardamine cordifolia, and Lepidium virginicum. source

Glucoraphanin, C₁₂H₂₃NO₁₀S₃, occurs in young sprouts of broccoli, Brussels sprouts, cauliflower, red cabbage, radish, cabbage. source

It is a precursor to sulforaphane, anti-cancer, anti-microbial.

glucoraphanin + myrosinase → sulforaphane C₆H₁₁NOS₂ source

Gluconic acid, C₆H₁₀O₇ source

Gluconobacter, Make wine from grape juice and vinegar from wine: 4.2.4

E575, glucono δ-lactone.

Aloenin¶

Aloenin, C₁₉H₂₂O₁₀, Aloearbonaside, bitter glucoside, occurs in Candelabra aloe, in skin care osmetics. source

Apterin, Coumarin, C₂₀H₂₄O₁₀ source

Arctiin, anti-tumour, antiviral, glucoside of Arctigenin, C₂₁H₂₄O₃, Arctium lappa, burdock source

Betanin, C₂₄H₂₆N₂O₁₃ source

Cycasin glucoside, C₈H₁₆N₂O₇ source

Fraxin, C₁₆H₁₈O₁₀ source

Icariin, C₃₃H₄₀O₁₅ source

21.0 Linamarin, C₁₀H₁₇NO₆ source

Piceid, C₂₀H₂₂O₈ source

Piceatannol

Picrocrocin, C₁₆H₂₆O₇ source

Quercitrin, C₂₁H₂₀O₁₁ source

Rhamnazin, C₁₇H₁₄O₇ source

Rhamnetin, C₁₆H₁₂O₇ source

Rhaponticin, C₂₁H₂₄O₉ source

Salicin, C₁₃H₁₈O₇ source

Myrosinase, (Enzyme)¶

Myrosinase, (Enzyme)

Myrosinase enzyme, also called: glucosinolase, thioglucosidase, thioglucoside glucohydrolase.

Myrosinase enzyme is a singrinase and a sinigrase.

glucosinolate + myrosinase → toxic compounds to deter grazing. source

glucosinolate + myrosinase → glucose + isothionate source

glucosinate + myrosinase → thiocynates (SCN-), and nitriles (R-C triple bond N) source

Glucotropaeolin¶

Glucotropaeolin, C₁₄H₁₉NO₉S₂, Benzyl glucosinolate, an aralkylglucosinolic acid, a benzene source

. It is a flavour component and a breakdown hydrolysis product, and the precursor of benzyl isothiocyanate, C₈H₇NS source

It is a strongly antibacterial, and antifungal.

It occurs in Cardamine cordifolia, Lepidium virginicum, nasturtium, garden cress, Indian cress, horseradish>, Papaya dry latex.

Glucuronic acid¶

Glucuronic acid, C₆H₁₀O₇, D-Glucopyranuronic Acid, Glucuronate, (GlcA), Uronic acid, first isolated from urine source

It occurs in many gums, gum arabic, Xanthan, Kombucha tea, animal liver.

It is formed by the oxidation of the C-6 carbon of glucose, and it can detoxify some drugs and toxins.

Glutaric acid¶

Glutaric acid, C₅H₈O₄, COOH(CH₂)₃COOH, Pentanedioic acid, an alpha omega-dicarboxylic acid, colourless crystals or white solid, corrosive, used to make polyamides and polyesters, irritates skin and eyes, may be associated with acidosis, dehydrogenase deficiency, brain damage, macrocephaly source

Gluten¶

Gluten, wheat starch and gluten (in wheat, barley, rye, gluten is gliadin + glutenin), gluten intolerance

Gluten proteins affect the baking quality of wheat by giving dough water absorption capacity, cohesivity, viscosity and elasticity.

Gluten proteins are divided into aqueous alcohol soluble gliadins and insoluble glutenins.

Gliadins are mainly monomeric proteins with molecular weights 28, 000-55, 000, and classified into alpha/beta-, gamma- and omega-types.

Disulphide bonds may be present as intrachain crosslinks.

Glutenins are aggregated proteins linked by interchain disulphide bonds, with molecular weights from 500, 000 to > 10 million.

After reduction of disulphide bonds, the resulting glutenin subunits are soluble in aqueous alcohols as with gliadins.

Glutenin subunits are divided into the high-molecular-weight subunits.

(MW=67, 000-88, 000) and low-molecular-weight subunits (MW=32, 000-35, 000).

Gliadin causes elasticity and tenacity, or toughness, to the gluten, and the glutenin gives it strength.

Gliadin, L-glutamine, C₅H₁₀N₂O₃, molecular weight 631.687 g/mol, a prolamine, from gluten of wheat and rye, toxic factor is associated with coeliac disease. source

Gluten powder, wheat starch, wheaten cornflour

Gluten intolerance: 19.2.5

Endospermic and non-endospermic seed: 9.109 (See: 2.2)

Experiments

Prepare lactic acid with sourdough: 4.2.3 (See: Gluten)

Tests for carbohydrates, Molisch's test: 9.3.7

Tests for starch with Fehling's solution: 9.142.3. (See: 4.)

Tests for wheat starch for gluten: 16.6.2

Glutinosone¶

Glutinosone>, C₁₄H₂₀O₂, occurs in Peruvian tobacco, (Nicotiana glutinosa), only after infection by tobacco mosaic virus. source

Glycan¶

A glycan is usually O-glycosidic linkages of monosaccharides.

Examples of glycans:

Cellulose is composed of β-1,4-linked D-glucose molecules

Chitin is composed of β-1,4-linked N-acetyl-D-glucosamine molecules

Glyceraldehyde

Glyceraldehyde, C₃H₆O₃, is sold as: DL-glyceraldehyde, D-(+)-glyceraldehyde source

Left-handed and right-handed structural forms, D-sugars and L-sugars: 16.3.1.3.1

Monosaccharides: 16.3.1.3

Test for reducing sugars: 9.3.6

Glycerol

Glycerol, glycerin, glycerine, is a product containing at least 95% glycerol, C₃H₈O₃, 1,2,3-propanetriol. source

The terms glycerine, glycerin, glycerol may have no precise meaning in different countries and in different products.

Glycerol, glycerin, glycerine, C₃H₈O₃, CH₂OH-CHOH-CH₂OH, 1,2,3-propantriol, propane-1,2,3-triol, trihydric alcohol, antifreeze source

Glycerol, trihydroxypropane 1,2,3-propanetriol, glycyl alcohol, glycerol USP, is oily so harmful if spilled on floor.

Glycerol for lubricating rubber stoppers, mounting medium for temporary microscope slides.

Glycerol, clear, viscous, colourless odourless syrupy fluid that readily absorbs moisture, propane-123-triol, propane-1,2,3-triol, glycerin jelly, BP. 290 oC, and decomposes, RD 1.26, absorbs water from air, miscible, soluble in water and alcohol, sweet taste and no smell and has no action on litmus paper.

Glycerol is used in cosmetics, toothpaste, shampoo, loosens stains, medical uses, manufacture of explosives and shaving cream.

It is a by-product of the manufacture of soap.

Glycerol was discovered by K. W. Scheele, 1779, who heated olive oil with lithage.

Use glycerine smeared in ice cube trays to avoid trays sticking to freezer shelf.

Use glycerine added to the final wash rinse to stop woollen garments stretching.

Use glycerine to lubricate household mincing machines.

Use glycerine, rubbed in before washing, to remove lipstick stains.

Glycerol-phthalic anhydrides, thermoset: 3.8.8

Glycerol, trihydric alcohols, glycerol: 16.1.3.0.2

Glycerine jelly, adhesive, microscope slides: 2.1

Glycerine oxidation: 12.1.6

Glycerine with borax solution: 12.1.5

Glycerine with cobalt chloride solution: 12.1.8

Glycerol-phthalic anhydrides: 3.8.8

Glycerides: 16.3.3.0.5

Heat glycerine with sugar to form carbon: 12.1.7

Prepare glycerine jelly: 2.1

Tests for glycerine: 12.7.4

Tests for glycerol: 12.5.11

Tests for glycerine: #12.7.4H">12.7.4

Experiments

12.1.8. Glycerine with cobalt chloride solution¶

12.1.8. Glycerine with cobalt chloride solution

Dissolve 5 g of cobalt chloride crystals in 2 cm of water in a test-tube then add 5 g of glycerine.

Heat the test-tube to see the red colour of the liquid turning to a violet colour.

Cool the test-tube to see the red colour return.

Glycogen¶

Glycogen, (C₆H₁₀₀₅)n, animal starch, liver starch, is a branched polymer of glucose synthesized by animal cells for energy storage. source

Glycogen is constructed mostly of α14 glycosidic bonds with branches created through α16 glycosidic bonds.

Glycogen is prepared from rabbit liver and from blue mussel, (Mytilus edulis).

Glycogen, starches, amylum: 16.3.1.5

Anatomy and physiology of meat: 19.3.2

Prepare Carnoy's solution: 4.8

Glycosides¶

See: Glycosides

1. Alcoholic glycosides, salicin occurs in Salix.

* Aldehyde glycosides, vanilla pod, glucovanillin, cinnamon bark cinnamic aldehyde

Anthocyanidins (aglycones of the glycoside anthocyanins), e.g. Cyanidin

2. Flavonoid glycosides

Hesperetin

Naringin

Rutin

Iridoid glycosides, monoterpenes
Isothionate glycosides, wild mustard
Lactone glycosides, sweet clover, red clover
Phenolic glycosides, arbutin (bearberry), Uva Ursi
Steroidal glycosides, cardiac glycosides
Steviol glycosides (aglycone steviol), Stevia, has 2 primary glycosides: stevioside, rebaudioside A.
Thioglycosides (contain sulfur), Sinigrin precursor to allyl isothiocyanate, mustard oil

3. List of glycosides by name:

Acetyldigoxin, cardiac glycoside

Acolongifloroside, cardiactive glycoside

Agnuside, iridoid glycoside

Aloe-emodin, anthraquinone glycoside

Alvonal MR, cardiac glycoside

Aloin, barbaloin, anthraquinone glycoside

Amarogentin, secoiridoid glycoside

Amikacin, aminoglycoside

Amygdalin, cyanogenic glycoside

Apiin, diglycoside

Arbutin, glycoside

Asiaticoside, triterpene glycoside

Baicalin, flavone glycoside

Bufalin, C₂₄H₃₄O₄, cardiac glycoside, (in toad venom) source

Calotropin, cardiac glycoside

Cascarosides, C₂₇H₃₂O₁₄ hydroxyanthracene glycoside source

Convallatoxin, C₂₄H₄₂O₁₀, cardiac glycoside source

Cornin, (Verbenalin), C₁₇H₂₄O₁₀, iridoid glycoside source

Deslanoside, cardiac glycoside

Dhurrin, C₁₄H₁₇NO₇, cyanogenic glycoside source

Digitoxin, C₄₁H₆₄O₁₃, cardiac glycoside source

Digoxin, C₄₁H₆₄O₁₄, cardiac glycoside source

Echinacoside, C₃₅H₄₆O₂₀, glycoside source

Gentamicin, C₂₁H₄₃N₅O₇, amminoglycoside source

Gentiopicrin, C₁₆H₂₀O₉, secoiridoid glycoside source

Hesperidin, C₂₈H₃₄O₁₅, flavanone glycoside source

Hypericin, C₃₀H₁₆O₈, Anthraquinone glycoside source

Lanoxicaps, (Digoxin) C₄₁H₆₄O₁₄, cardiac glycoside source

Lanatoside C, C₄₉H₇₆O₂₀, cardiac glycoside source

Linamarin, C₁₀H₁₇NO₆, cyanogenic glycoside source

Lotaustrain, C₁₁H₁₉NO₆, cyanogenic glycoside source

Mangiferin, C₁₉H₁₈O₁₁, glycoside source

Metildigoxin, C₄₂H₆₆O₁₄, digitalis glycoside source

Naringin, flavonoid glycoside

Netilmicin, C₂₁H₄₁N₅O₇, aminoglycoside source

Oleandrin, C₃₂H₄₈O₉, cardiac glycoside source

Ouabain, C₂₉H₂₄O₁₂, cardiac glycoside source

Phillyrin, C₂₇H₃₄O₁₁, lignan source

Physcion, C₁₆H₁₂O₅, anthraquinone source

Proscillaridin A, C₃₀H₄₂O₈, cardiac glycoside source

Prunasin, C₁₄H₁₇NO₆, cyanogenic glycoside source

Pseudohypericin, C₃₀H₁₆O₉ source

Rutin, glycoside

Rebaudioside, C₄₄H₇₀O₁₃, glycoside source

Rhamnazin, C₁₇H₁₄O₇, flavonol glycoside source

Rhamnetin, C₁₆H₁₂O₇, flavonol glycoside source

Rosarin, C₂₀H₂₈O₁₀, cinnamyl alcohol glycoside source

Scillaren A, C₃₆H₅₂O₁₃, cardiac glycoside source

ShatavarinIV, C₄₅H₇₄O₁₇, asparanin B source

Sisomycin, C₁₉H₃₇N₅O₇, aminoglycoside source

Sophoricoside, C₂₁H₂₀O₁₀, isoflavone glycoside source

Stevioside, C₃₈H₆₀O₁₈, steviol diterpene glycoside source

Strophanthin, C₃₆H₅₄O₁₄, cardioactive glycoside source

Verbascoside, C₂₉H₃₆O₁₅, glycoside source

Gold¶

Gold, Table of the Elements

See: Gold, RSC

Carat: Carat

Gold, Au, natural gold, for medical use: 35.2.35, (Geology)

Gold leaf electroscope: 31.145

Golden, (Experiments)

Ores and ore bodies: 35.5.0, (Geology)

Gold properties:

Gold, Au (old English golde ), yellow, resists corrosion, transition series metal, malleable, ductile

Gold beads, evaporation slug, foil, powder, nanopowder, rod, sponge, wire, microrods, nanorods, nanowires

Gold, Au (aurum) is a yellow, lowest metal in the reactivity series, so most unreactive transition metal, is found in nature as free element form.

Gold is available as gold leaf and is used in coin alloys, electrical components, dentistry alloys, jewellery and as a monetary standard.

Jewellery rings are not usually made from pure gold, because they would scratch easily.

White gold is usually gold alloyed with white metals, e.g. silver, palladium, manganese, nickel, which makes the gold ring whiter.

Yellow gold, the most popular alloy, is usually gold alloyed with zinc or copper, 18 K or 14K, for engagement or wedding rings, making it malleable and easier to work, but easily scratched or dented.

Gold alloyed with copper only, makes the gold ring redder, but with zinc and copper makes the gold ring harder.

No reaction with dilute HCl or H₂SO₄, air, water or concentrated oxidizing acids, e.g. HNO₃ or H₂SO₄. source

Reacts with aqua regia, "royal water", that dissolves gold, the "king of metals" to form AuCl₄. source

Atomic number: 79, Relative atomic mass: 196.967, RD 19.3, m.p. = 1063 oC, BP = 2970 oC

Gold catalysts:

Acetonitrile, C₂H₃N, (2-biphenyl)di-tert-butylphosphine], gold(I) hexafluoroantimonate, C₂₂H₃₀AuF₆NPSb source

Bis[chlorogold(I)], 1,1-bis(diphenylphosphino)ferrocene, C₃₄H₂₈Au₂Cl₂FeP₂ source

Chloro[(1,1-biphenyl-2-yl)di-tert-butylphosphine]gold(I), C₂₀H₂₇AuClP source

Chlorocarbonylgold(I), CAuClO

Chloro(dimethylphenylphosphine)gold, C₈H₁₁AuClP source

Dichloro(DPPE)digold(I), C₂₆H₂₄Au₂Cl₂P₂ source

Gold (III) bromide, AuBr₃ source

Gold (I) chloride, AuCl

Gold (III) chloride, AuCl₃ source

Gold (III) chloride trihydrate, HAuCl₄.3H₂O source

Gold (I) iodide, AuI

Prepare goldenrod indicator, electric writing: 5.6.3.3

Methyl(triphenylphosphine)gold(I), C₁₉H₁₈AuP source

Sodium tetrachloroaurate(III) dihydrate, AuCl₄Na.2H₂O source

Trichloro(pyridine)gold(III), C₅H₅AuCl₃N source

Tris(triphenylphosphinegold)oxonium tetrafluoroborate, C₅₄H₄₅P₃OAu₃BF₄ source

Golden

Attract water to a comb: 31.41, (See: 3. "Golden Syrup".

Cellophane as a semipermeable membrane: 9.165, (See: 3. "Golden syrup".)

Density of different liquids: 11.4.6.2, (See: 1.0 "Golden syrup".)

Golden syrup

Goldenrod indicator, electric writing: 5.6.3.3

Goldenrod oil, (Solidago canadensis), Asteraceae

Goldenseal, (Hydrastis canadensis), Ranunculaceae

Touchstone, gold streak: 35.1.15

Ormolu¶

Ormolu looks like gold by coating brass with copper zinc tin alloy called gilt brass.

Ormolu was gilded bronze using gold-mercury amalgam, but dangerous procedure, so nowadays electroplated with gold.

It is used for ormolu-decorated mantlepiece clocks, furniture, porcelain

Greenhouse gases¶

Composition of the atmosphere and greenhouse gases: 37.2.2

Greenhouse effect in a model greenhouse: 37.2.6a

Global warming and climate change: 37.1.3

Test for carbon dioxide as a greenhouse gas: 3.5.1

Guanine¶

Guanine, C₅H₅N₅O, (2-Amino-6-hydroxypurine), constituent of nucleotides, occurs in nucleic acids, unsaturated planar bicyclic molecule. source

It was first found in sea birds, which excrete guano, which is used as a fertilizer.

In DNA and RNA, stretches of guanine bases are reported to form stable four stranded helices.

Guanine, DNA and RNA: 9.4.0, (See 3.)

Guanine, Nucleic acid nitrogenous bases: 3.0.0

Guanosine, C₁₀H₁₃N₅O₅, (guanine + D-ribose) source

Gums¶

Resins and gums: 3.0.0

Gum arabic: 16.3.2.9

Gum guar, Gum locust bean, Gum tragathanth, Gum mastic, used as chewing gum and Greek food flavouring, from Pistacia lenticus , Anacardiaceae

Gum rosin includes: colophony, Greek pitch, used on violin bows and ballet shoes

Abietic acid

Gummi bears: 15.4.12, (gummi fruit), with potassium chlorate

Guttapercha¶

Gutta percha, a diene polymer

Stereoisomers:

Gutta percha, trans-1,4-polyisoprene, crystallizes
Latex or natural rubber, cis-1,4-polyisoprene, amorphous and non-crystalline

It is hard and non-brittle, and becomes soft and impressible at 100 oC.

It is obtained from milky latex of the Getah Perca tree (Malay) (Palaquium gutta).

It was used for golf balls, but is now used only for root-canal endodontics, and locally-made handles for knives and walking sticks.

GABA¶

Gamma-Aminobutyric acid, C₄H₉NO₂, inhibitory neurotransmitter, brain relaxant, anti-seizure, anti-anxiety source

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