School Science Lessons
Topic 16
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16 Organic chemistry, tests for organic compounds
Table of contents
See: OrganicChemistry (Commercial)
See: Chemicals, (Commercial) Acetal Acetates (ethanoates) Acetylene, C2H2, ethyne Acid anhydrides Acyl halides Acrylamide Acyclic hydrocarbons
16.1.01 Addition reactions Alcohols, phenols, thiols
3.8.0 Alcohols, Fatty alcohols, lauryl alcohol Alcohol, Ethanol safety Aldehydes Alkaloids from plants Alkanes (CnH2n+2), paraffins Alkenes (CnH2n), olefins Alkynes (CnH2n-2), acetylenes Amides Amines Arenes, benzene Benzoyl group
Bisphenol-A (BPA), Epoxy resin polymer Carbamates Carbides Carboxylic acids and fatty acids Carbonyls
Carvacrol, C10H14O
18.7.23 Chloramines in swimming pools Clenbuterol, C12H18Cl2N2O
16.2.10 Coal tar products, creosote Cyanamides, inorganic (CN22-), Cyanocrylates, "Superglue"
16.14.0 Dioxins, "Agent orange", PCBs
9.10.0 EDTA, ethylenediaminetetraacetic acid
16.6.1 Essential oils, volatile oils, ethereal oils
16.5.0 Esters, derivatives of fatty acids Ethane (C2H6) Ethers, group: (-O-), in organic compound Ethyl cellulose Epoxy resin polymers Ethylenediamine
16.6.2 Fixed oils, non-volatile oils Fluorescent liquids
16.1.12 Fractional distillation of crude oil Imides, imido group: (-CONHCO-) Imines, imino group: -NH-, or =NH Cyclic imines
Methane, natural gas Methyl bromide, bromoethane, CH3Br Methylamine ionization reaction
16.2.4 Nitrogen compounds, one atom of nitrogen Nitrogen compounds, two or more nitrogen atoms Nitrosamines Nitramine (acid-base indicator) Nitriles Nitrites (NO2-) Nitroalkanes (nitroparaffins)
16.1.0 Organic chemistry
16.2.3 Organometal compounds
16.1.03 Oxidation reactions, loss of electrons Oximes (hydrox-imino-alkanes) (C:NOH)
16.2.6 Phosphorous compounds
3.32.0 Prepare gases, gas generation apparatus
16.1.00 Prepare organic compounds Prepare phenylamine Quinones
16.1.04 Reduction reactions, gain of electrons
Ribose, C5H10O5
Ribulose, C5H10O Salts, organic salts, sodium ethanoate Saturated hydrocarbons, hexane, C6H14 Sulfur organic compounds Tests for organic compounds
16.6.3 Vegetable oils, Plant oils Acyclic hydrocarbons Acyclic hydrocarbons, alkanes, alkenes Alkanes (CnH2n+2), paraffins Arenes, benzene (C6H6) Butane (C4H10) Prepare butane Combustion of butane Cycloalkanes Ethane (C2H6) Prepare ethane gas Hexane (C6H14) Heptane (C7H16)
LPG (Liquefied Petroleum Gas, LP gas)
Methane, natural gas Octane (C8H18), Octane number Octadecan-1-ol (C18H38O) Octanol, [CH3(CH2)7OH] Pentane (C5H12) Propane (C3H8) Alkanes (CnH2n+2), paraffins
Alkanes, cyclohexane, heptane, hexane, liquefied petroleum gas (LPG), octane, pentane, petroleum spirit
Alkanes: methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane. Alkanes (CnH2n+2), paraffins
Alkanes, skeletal formula: See diagram 16.1.1 Alkanoic acids, RCOOH, -oic acids Acyclic hydrocarbons, alkanes, alkenes, alkynes
Iodine value
3.29.0 Collect and weigh the gaseous products of a burning candle Friedel-Crafts reaction Nitroalkanes (nitroparaffins), (CnH2n+1NO2) Oximes (hydrox-imino-alkanes), Group: (C:NOH) Petroleum gas (See to Tests for unsaturated alkanes (Experiments) Alkenes (CnH2n), olefins
Alkenes (CnH2n), olefins Prepare ethene (ethylene), C2H4 Dienes, diolefins Arenes, benzene Arenes, benzene Phthalic acid Friedel-Crafts reaction Nitration (Experiment) Alcohols, phenols, thiols
Alcohols, R-OH, -OH hydroxyl, Prefix: hydroxy-, Suffix: -ol (-OH: alcohol), (alkanol, alkyl alcohol)
6.6.18 Alcoholic fermentation, yeast Saccharomyces cerevisiae (Exp.) Alcohols Alcohols, primary, secondary and tertiary aliphatic alcohols Tests for alcohols, potassium manganate (VII)
16.1.3b Butanol (C4H9OH)
16.1.3c Butyl glycol (C4H9OCH2CH2OH)
16.1.0 Carbolic acid, phenol, TCP, Dettol Cresols Dihydric alcohols, glycol
16.5.0 Ethanol
1.4 List of alcohols
16.5.1 Methylated spirits Naphthols Nitroglycerine (UK), nitroglycerin (USA) Nitrocellulose, gun cotton
12.12.4 Oxidation of glycerol by potassium permanganate Phenols Polyhydric alcohols
4.3.8 Prepare alcohol using immobilized yeast cells (Exp.) Prepare sodium ethoxide
16.1.3a Propanol (C3H7OH) Pyrogallol Resorcinol
16.1 3.2.5 Triclosan, organohalogens Trihydric alcohols, glycerol Thiols (mercaptans)

16.1.13 Prepare triodomethane, (iodoform)
16.1.14 Prepare trichloromethane gas (chloroform) Reaction of acetone with bleaching powder Reaction of ethyl alcohol with bleaching powder Carbides Carbides
Methanides, aluminium carbide, Al4C3
Acetylides, calcium carbide CaC2
Sesquicarbides, e.g. Mg2C3
Covalent carbides, boron carbide, carborundum
Silicon carbides (Carborundum)

16.1.12 Fractional distillation of crude oil
Fractional distillation of crude oil
Hydraulic fluid
Mineral oil Petroleum gas (methane, ethane, propane, butane), LPG Naphtha (ligroin), processed to make gasoline Petrol, "gas", gasoline, motor fuel Kerosene, kerosine, paraffin oil, jet engine fuel, tractor fuel Diesel oil, gas oil or diesel distillate, diesel fuel, heating oil Lubricating oil, motor oil, grease Paraffin wax, heavy gas, fuel oil Residuals, bitumen, "tar", asphalt, waxes, petroleum jelly Nitrogen compounds, two or more nitrogen atoms Azide compounds Azo compounds Diazo compounds Sulfur organic compounds
Sulfur compounds (For the "thio" prefix, replace oxygen by sulfur, e.g. thiobenzamide [PhC(=S)NH2]) Isothiocyanates Sulfides
Diallyl sulfide
Diallyl disulfide Sulfonium compounds Thiocyanates Silicones Siloxanes Sulfoxide Thiols (mercaptans) Allyl mercaptan Methanethiol from asparagus Methyl mercaptan Ethyl mercaptan, ethanethiol Thiophene, thiolane, THT Phenothiazine, PTZ

16.1.0 Organic chemistry, Carbon, C
See: Organic Chemistry (Commercial)
See diagram 16.0.0: Organic chemistry functional groups
See diagram 16.0.1: Tetrahedral geometry of carbon, methane molecule, isobutyl alcohol
Organic chemistry is the chemistry of carbon compounds.
Hydrocarbons contain carbon and hydrogen only.
The main types are the alkanes, alkenes and alkynes.
In alkenes and alkynes, addition reactions occur at the double bonds = or triple bonds.
Triple bond (has 6 electrons in the bond), e.g. Carbon monoxide, C≡O
Be careful!
When heating organic chemicals, do not point the test-tube towards anyone!
Organic compounds may suddenly vaporize and spurt out of the test-tube!
1. Classification by molecular framework
1.1 Acyclic compounds have chains of unbranched or branched carbon atoms
1.2 Carbocyclic compounds have rings of carbon atoms
1.3 Heterocyclic compounds have rings of carbon atoms with one atom in a ring not carbon, e.g. O, N, S
2. Classification by functional group, e.g. hydroxyl group, OH, is characteristic of alcohols

16.1.00 Prepare organic compounds
16.1.01 Addition reactions
16.1.02 Substitution reactions (displacement reactions)
16.1.03 Oxidation reactions, loss of electrons
16.1.04 Reduction reactions, gain of electrons

16.1.01 Addition reactions
Atoms are added to the two atoms of a double bond or triple bond in an unsaturated compound, also when no atoms are replaced,
but extra covalent bonds are formed.
Alkenes (olefins) or alkynes (acetylenes) --> haloalkanes (alkyl halides), or primary alkanols (alcohols), or secondary alkanols, (alcohols)
Example: HCl + CH2CH2 --> CH3CH2Cl

16.1.02 Substitution reactions, (displacement reactions)
Replacement of an atom or group in a molecule by another atom or group
Alkanes (paraffins) --> haloalkanes (alkyl halides) --> amines
Haloalkanes (alkyl halides) <--> primary alkanols (alcohols), (-CH2-OH)
Alkanoic acids --> esters --> amides
Example: CH4 + Cl2 --> CH3Cl + HCl [chlorination produces chloromethane (methyl chloride) and HCl.]

16.1.03 Oxidation reactions, loss of electrons
Primary alcohols can be directly oxidized to aldehydes or carboxylic acids
Primary alkanols (alcohols) (-CH2-OH) --> alkanals (aliphatic aldehydes)
Example: CH3OH + O2 --> CH2O + H2 (Pt catalyst) [Oxidation of methanol to methanal using a platinum catalyst]
Alkanals --> alkanoic acids, e.g. butanoic acid, CH3(CH2)2COOH
Secondary alkanols (alcohols) (CH3)2CHOH --> alkanones
Alkanones (ketones, RCOR'), simplest ketone: acetone (2-propanone, dimethyl ketone), O=C(CH3)2

16.1.04 Reduction reactions, gain of electrons
9.142 Fehling's test
Alkanals (aliphatic aldehydes) --> primary alkanols (alcohols), (-CH2-OH)
Add drops of formalin to a test-tube one quarter filled with Fehling's A and B solutions and heat to boiling.
Note the yellow then orange then red precipitate of copper (I) oxide.
The copper from the copper (II) sulfate solution has been reduced from copper (II) to copper (I). Acyclic hydrocarbons, alkanes, alkenes, alkynes
| See diagram 16.1.1: Alkanes, alkenes, alkynes
| See 10.6.3: Distil crude oil and collect the fractions
Alkanes, alkenes, alkynes or their derivatives are aliphatic compounds, i.e. non-cyclic organic compounds.
Acyclic molecules have carbon atoms in chains but not in rings.
The chains may be unbranched or branched.
Aromatic compounds contain a benzene ring in the molecule.
Hydrocarbon compounds contain only hydrogen and carbon.
Hydrocarbons are usually colourless and have low solubility in water.
Crude oil is a mixture of hydrocarbons.
Hydrocarbons may be saturated, i.e. have only single bonds, or unsaturated, i.e. contain multiple bonds, e.g. double bond =, or triple
bond, carbon monoxide, C≡O.
Iodine value is the number of grams of iodine absorbed by 100 g of fat or oil, to indicate the amount of unsaturated acids. Alkanes (CnH2n+2), paraffins
The first 10 unbranched alkanes and molecular formula: methane (CH4), ethane (C2H6), propane (CH3H8), butane (CH4H10),
pentane (CH5H12), hexane (CH6H14), heptane (CH7H16), octane (CH8H18), nonane (CH9H20), decane (CH10H22).
Alkanes burn in oxygen to give carbon dioxide and water.
Candle wax is a mixture of different alkanes that are solid at room temperature.
Alkanes are usually associated with natural petroleum deposits and can be distilled from petroleum.
1. Alkanes (paraffins) are saturated hydrocarbons, i.e. all single bonds between C atoms, have formula CnH2n+2 and names end in "ane".
The names of unbranched alkanes come from the number of carbon atoms.
The name of branched alkanes come from the longest chain of carbon atoms.
The hydrocarbon branches, alkyl groups, symbol R, are formed by removing one hydrogen atom from the alkane and named by
 changing the "ane" to "yl", e.g. methane, CH4 to methyl, CH3-, also "Me".
The carbon atoms of the longest continuous name are numbered starting at the end of the chain closest to the first branch, e.g. an
eight carbon chain with an ethyl group attached to carbon 5 and a methyl group attached to carbon 3 and carbon 4 is called
5-ethyl-3, 4-dimethyloctane.
Saturated hydrocarbons, e.g. hexane, C6H14, all carbons have either four or three hydrogens bonded to them and no double bonds,
triple bonds or rings, react in almost the same way.

2. Formation of alkanes
2.1 Hydrogenation of alkenes --> alkanes
CH2=CH2 + H2 --> CH3-CH3 (Pt catalyst)
ethylene + hydrogen --> ethane
CH3CH=CHCH3 + H2 --> CH3CH2CH2CH3 (Pt catalyst)
2.2 Decarboxylation (remove CO2) from molecules that have - COOH group.
RCOONa + NaOH --> R-H + Na2CO3 (dry distillation with soda lime)
CH3COONa + NaOH --> CH4 + Na2CO3 Alkanoic acids, RCOOH, -oic acids
Butanoic acid, C3H7COOH, butyric acid
Ethanoic acid, CH3COOH, acetic acid, vinegar
Methanoic acid, HCOOH, formic acid:
Propanoic acid, propionic acid, C2H5COOH,
Isobutyric acid, Cycloalkanes
Cycloalkanes, CnH2n, cycloolefins, cyclanes, polymethylenes, cycloparaffins, saturated carbon rings.
Cycloalkanes are saturated hydrocarbons with a ring of carbon atoms,
e.g. The position of branches depends on the alphabetical order of the branch names so that highest in order is attached to carbon 1,
e.g. 1-ethyl-2-methylcyclopropane.
Cyclopropane, C3H6, colourless gas, former anaesthetic, petroleum odour, easily ignited, may cause frostbite, containers may explode
Cyclobutane, C4H8, tetramethylene, condenses to liquid at 13oC, insoluble in water, containers may explode
Cyclopentane, C5H10, pentametylene, colourless liquid, flash point -37oC, insoluble in water
Cyclohexane, C6H12, hexamethylene
Cycloheptane C7H14, heptamethylene, colourless oily liquid, flash point 16oC, narcotic effect
Cyclooctane C8H16, octamethylene Arenes, benzene
See Aromatics, aromatic compounds, benzene derivatives, arenes
See diagram 16.8.1: Benzene compounds
Benzene, C6H6, has a stable six-sided ring structure.
Arenes, e.g. benzene, naphthalene, anthracene, phenanthrene.
Arenes do not mix with water, but they do mix with hydrocarbons and all non-polar solvents.
Arenes usually burn with a smoky flame, as do most aromatic compounds, because of the high carbon: nitrogen ratio.
So when they burn in air, some carbon soot usually remains in the air.
Arenes are called aromatic compounds because the first arenes were isolated from fragrant oils.
However, nowadays aromatic refers to the structure not the smell. Phthalic acid
Phthalic acid, C8H6O4, benzene-1, 2-dicarboxylic acid, formerly derived from naphthalene.
Phthalic anhydride, benzene-1, 2-dicarboxylic anhydride, phthalandione, Toxic, strong skin irritant
Phthalic anhydride, C8H4O3, used to produce phthalic esters, chemical plasticisers, plastics from vinyl chloride.
3.0.4 Phthalates Nitration
See 10.01.10: Liebig condenser
12.7.01 Nitration
Substitution of a -NO2 group for a hydrogen atom in an arene ring, e.g. bromine.
The reaction substitutes a hydrogen atom in an arene ring by a -NO2 group.
Heat benzene with a mixture of nitric and sulfuric acid catalyst in a Liebig condenser at 330 K.
benzene + HNO3 --> benzene-NO2 + H2O
benzene + NO2+ --> benzene-NO2 + H+
Also, some 1.3-dinitrobenzene may form. Friedel-Crafts reaction
The reaction substitutes a hydrogen atom in an arene ring of a halogen alkane by an organic group, R, using aluminium chloride catalyst.
RCl + AlCl3 --> R+ + AlCl4-
For example, benzene with chloromethane forms methyl benzene.
benzene + CH3+ --> benzene-CH3 + H+
CH3Cl +AlCl3 --> CH3+ + AlCl4- Tests for unsaturated alkanes
1. Ignition tests for unsaturation
Ignite a substance in an evaporating basin and observe the smoke over the flame.
The darker or more sooty the smoke, the more unsaturated, e.g. aromatic compound.
If clear over a luminous flame the compound is saturated, e.g. n-hexane.

2. Bromine tests for unsaturation.
Bromine is a coloured compound but it reacts with double bonds or triple bonds to form a colourless brominated compound.
alkene or alkyne + bromine water, yellowish colour disappears.

3. Decolorization of bromine water.
Hexane does not decolorize bromine water.
Aromatic compounds also do not decolorize bromine water because they are stable compounds.

4. Baeyer test
Change in colour of the reagent (purple permanganate to brown manganese dioxide), redox reaction
Brominate hexane and other saturated hydrocarbons with the right wavelength of light and shining it on the reaction vessel, or adding
peroxide or by heating the reaction. Ethane (C2H6)
| See 3.32.0: Prepare gases with a gas generation apparatus, Collect insoluble gases over water.
| See diagram 16.1.1: Ethane
Ethane is a colourless and odourless gas, which has properties similar to methane. Prepare ethane gas
This experiment was called the "wet asbestos method" because asbestos wool, was used to soak up methyl iodide in the test-tube.
However, asbestos wool is not allowed in schools.
Pour 2 cm methyl iodide in a test-tube.
Add 5 g of copper turnings and push it down firmly with a spatula.
Set up the apparatus and heat the mixture.
2CH3I + 2Cu --> C2H6 + Cu2I2 Propane (C3H8)
Colourless liquefied petroleum gas, a bottled gas, b.p. -42.2oC, catalytic cracking forms propylene, propellant, aerator, fuel for gas
barbecue and blow torch LPG (Liquefied Petroleum Gas, LP gas)
LPG is a clean burning fuel and is stored in gas cylinders as bottled gas.
LPG is a simple asphyxiant.
It consists of propane (about 95%) together with varying proportions of butane, propylene and butylene.
A bad smelling compound is added so that the presence of the gas can be easily detected.
Incomplete combustion forms carbon monoxide.
Do not search for a gas leak with a lighted match or lighted taper, but use a soap solution. Butane (C4H10)
| See diagram 3.32: Collect insoluble gases over water, See 3.
| See diagram 16.1.2: Butane isomers
n-Butane, b.p. -0.5oC, relative density 0.60 at 0oC, is stored as liquid under pressure in steel cylinders giving
Calor gas and cigarette lighter gas. (in cigarette lighters and portable gas appliances)
Butane is a Highly flammable gas at room temperature, vapour pressure 2.4 atm.
Butane gas is stored as liquid under pressure in fire lighters.
If lighter trigger is squeezed, canister opens and liquid forms a vapour.
Cigarette lighter fuel is 90% butane, isomer isobutane.
Sudden decompression in aircraft can cause butane cannisters to rupture. Prepare butane
This experiment was called the "wet asbestos method" because asbestos wool was used to soak up the ethyl iodide in the test-tube.
However, asbestos wool is not allowed in schools.
Pour 2 cm ethyl iodide in a test-tube.
Add 5 g of copper turnings and push it down firmly with a spatula.
Set up the gas generation apparatus and heat the mixture.
2C2H5I + 2Cu --> C4H10 + Cu2I2 Combustion of butane
Butane / Oxygen combustion
2C4H10 + 13O2 --> 8CO2 + 10H2O + energy Pentane (C5H12)
Pentane, b.p. 36.3oC, relative density 0.63, is made by distillation of petroleum. Hexane (C6H14)
Hexane, b.p. 68.7oC, relative density 0.66, exists as five compounds with same formula, normal hexane, n-hexane, in petrol and
petroleum ether solvent, colourless liquid ethereal odour.
"Shellite" (Australia) is 60% hexane and 40% heptane. Heptane (C7H16)
Heptane, b.p. 98oC, relative density 0.68, nine isomers, normal heptane has similar properties to normal hexane. Octane (C8H18), Octane number
See diagram 16.1.1h: Octane ratings
Octane, b.p. 126oC, relative density 0.702 at 20oC, exists as eighteen compounds, in petroleum.
Isomeric with iso-octane, 2, 2, 4-trimethylpentane (CH3)3CCH2CH(CH3)2.
Octane number
See: Spark plugs, pre-ignition
Some hydrocarbons with unbranched carbon chains prematurely explode in the cylinder and produce an audible knocking sound or
"ping" sound (knocking, pinking).
A scale of "knock property" has isooctane (2, 2, 4-trimethylpentane) at 100 (a good fuel) and heptane at 0 (a poor fuel).
So gasoline with octane number 80 has the same properties as a mixture of 80% isooctane and 29% heptane.
Octane number is the percentage of iso-octane normal heptane mix with the same knocking behaviour of the fuel being tested, so it
indicates the knock rating of a motor fuel.
A high octane fuel has a longer self-ignition delay in motor car engine.
In Brisbane, most " family cars" use 91 octane "unleaded petrol".
This is the lowest octane rating of the different petrol sold in garages.
A high octane rating of a fuel means that it has less tendency to pre-ignite in a high compression engine.
Pre-ignition means that before the spark plug has fired, the fuel air mixture burns because of heat created in the cylinder by compression.
Unleaded petrol has the octane rating 98.
Table 16.1.1h
Engine compression ratio 4:1 5:1 6:1 7:1 8:1 9:1 10:1 11:1 12:1
Octane number to be knock-free 60 73 81 87 91 95 98 100 102 Octadecan-1-ol, C18H38O
Octadecan-1-ol, C18H38O, octadecyl alcohol, 1-octadecanol, stearyl alcohol
Use octadecan-1-ol for melting point curve experiments., Octanol, CH3(CH2)7OH
Octanol, CH3(CH2)7OH, 1-octanol, octyl alcohol, n-octyl alcohol, octan-1-ol, caprylic alcohol, Flammable
3.10.0 Poisons and First Aid: See Octanol Alkenes (CnH2n), olefins
Alkene, R1R2C=CR3R4 (double CC bond =), Prefix: alkenyl-, Suffix: -ene (no principal functional group)
Alkene (olefins, olefines), CnH2n, e.g. ethylene, ethene C2H4, ethene (ethylene) (H2C=CH2), amylene, propadiene (allene)
 (R2C=C=CR2), dienes buta-1.2-diene, (CH3CH=C=CH2), amylene
See diagram 16.1.1: Cyclodienes, cis-trans alkenes
1. Suffix: -ene for C=C (olefin, olefins, olefines) are unsaturated hydrocarbons with at least one double bond between C atoms, C=C.
Alkenes have the formula CnH2n.
Alkenes include ethene (ethylene, C2H4, CH2=CH2), ethenyl (vinyl CH2=CH-), 3-propenyl (allyl, CH2=CH-CH2-), e.g. vinyl chloride
(chlorethene, CH2CHCl), allyl chloride (3-chloropropene CH2=CH-CH2Cl).
(In the textile trade "olefin" refers to synthetic fibre, polyolefin fibre, that are long-chain polymers of ethylene or propylene,
i.e. polyethylene (polypropylene, PP).
Alkenes decolorize acidified potassium permanganate solution and bromine solution.
2. The cycloalkenes, cycloolefins, are closed chain, non-aromatic forms, e.g. cyclopropene, CH.CH.CH2, cyclobutene, cyclopentene,
cyclohexene. Prepare ethene (ethylene), C2H4
See 3.32.0: Prepare gases with a gas generation apparatus
The preparation is an example of the dehydration of an alcohol.
1. Slowly add 10 mL of concentrated sulfuric acid to 5 mL of ethanol and 1 g of powdered aluminium sulfate in the gas preparation
Be careful!
Pass the gas formed through sodium hydroxide solution to remove sulfur dioxide and carbon dioxide!
Collect the gas over water.
Heat only if necessary.
Pass the gas through sulfuric acid as dehydrating agent.
CH3CH2OH --> H2C=CH2 + H2O

2. Add 3 mL ethanol to a plug of glass wool in a boiling tube.
Glass wool is not recommended for use in school laboratories.
Cover the glass wool with porous pot and heat the porous pot.
C2H5OH --> C2H4 (g) + H2O

3. This experiment was called the "wet asbestos method" because asbestos wool was used to soak up the ethyl iodide in the test-tube.
However, asbestos wool is not allowed in schools.
Pour 2 cm methyl iodide in a test-tube.
Add 5 g of copper turnings and push it down firmly with a spatula.
Set up the apparatus and heat the mixture.
2CH3I + 2Cu --> C2H6 + Cu2I2

4. Prepare ethene with ethanol, method 1.
See 3.96: Breakdown ethanol to ethene (ethylene)
Put some cleaned and dried unglazed porcelain chips in a flask.
Add 10 mL of pure ethanol (absolute alcohol).
Slowly pour 30 mL of concentrated sulfuric acid down the sides of the flask.
Be careful!
Shake the flask gently under cool water to avoid alcohol being carbonized because of increase in temperature.
Fit the flask with a thermometer and a delivery tube inserted in a two-holes rubber stopper.
Heat the flask to raise the temperature quickly to 170oC, then control at 170oC.
This heating procedure is used to increase the use ratio of ethanol and decrease by-products.
Wait until exclusion of the air in the flask and then collect the produced ethene gas over water.
Concentrated sulfuric acid and sodium hydroxide solution can be used to absorb and remove the small quantities of the ethyl ether
(sulfuric ether) vapour, carbon dioxide and sulfur dioxide present in the produced ethene.
C2H5OH (l) -> C2H4 (g) + H2O at 170oC.

5. Prepare ethene with ethanol, method 2.
See diagram 16.10.3: Prepare ethene
Absorb ethanol in cotton wool and push this to the bottom of a hard glass test-tube.
Pack small pieces of unglazed porcelain in the middle of the test-tube.
Fit a delivery tube to collect ethene gas over water.
First heat the porous pot strongly and then heat gently the cotton wool to produce some ethanol vapour.
This vapour breaks down over the hot porous pot to produce ethene gas and water vapour.
The temperature should be above 170oC otherwise the reaction produces dimethyl ether.
Collect the ethene over water.
Be careful! Disconnect the delivery tube when heating stops to avoid a suck back of water onto the hot porous pot. Dienes, diolefins
1. Dienes are alkenes with two C double bonds in the molecule, CnH2n-2, (same formula as alkynes, so dienes are alkyne isomers).
2. Cumulated dienes have two C double bonds next to each other, e.g. 1, 2-propadiene, H2C=C=CH2.
3. Conjugated dienes have two double bonds separated by a single bond, e.g. (buta-1, 3-diene) (CH2=CH-CH=CH2) and
(1, 3-pentadiene) (H2C=CH-CH=CH-CH3).
4. Unconjugated dienes, have two double bonds separated by two or more single bonds
5. Cyclodienes, 1.3-cyclohexadiene, 1.4-cyclohexadiene Trienes
Trienes have three C double bonds in the molecule, CnH2n-4, e.g. C6H8 (1, 3, 5-hexatriene)
Menthatriene, C10H14, (1, 3, 8-p-menthatriene) (para-menthatriene), terpene, camphor, woody aroma and taste, not used for
fragrances of flavours, colourless-yellow liquid, roasted odour, not used for fragrances of flavours, parsley aroma | in Parsley |
Jesuit's tea | Alkynes (CnH2n-2), acetylenes
Alkyne, R1-CC-R2 (triple CC bond involves 6 electrons, e.g. acetylene, HCCH).
Alkyne, Prefix: alkynl-, Suffix: -yne (no principal functional group), (acetylenes)
1. acetylenes: ethyne (acetylene) (C2H2 (HCCH), isoprene, methylene
Suffix: (-yne), for (CC) (acetylenes), are unsaturated hydrocarbons with at least one triple bond (), between C atoms, include ethyne
(C2H2), acetylene (HCCH), 3-propargyl (propargyl), (HCC-CH2-).
Alkynes decolorize acidified potassium permanganate solution and bromine solution.
2. The cycloalkynes are closed chain, non-aromatic forms, e.g. cyclooctyne, C8H12 (the smallest form). Acetylene, C2H2, ethyne Prepare acetylene Tests for acetylene Tests for gases from burning hydrocarbons, oxyacetylene welding Oxyacetylene welding Alcohols
See diagram 16.0.1: Tetrahedral geometry of carbon, methane molecule, isobutyl alcohol
Alcohols, CnH2n+1OH, ROH (-ol), alkanols, the two simplest alkanols: methanol (methyl alcohol) (CH3OH), and ethanol (ethyl
alcohol) (C2H5OH), in alcohols, ROH, the R is not specific.
Alkanol is a type of alcohol ROH, but R must be an alkane molecule.
Alkanol, aliphatic alcohol, alkyl alcohol, ROH (Prefix: hydroxy-), (Suffix: -ol) (-OH: alcohol)
Alcohols are organic compounds with the functional group -OH, but when attached to an aromatic ring called phenols.
Alcohols, alcohols group: (-OH) Suffix: (ol)
Primary alcohols
Methanol, CH3OH
1-butanol, butan-1-ol, n-butyl alcohol, CH3(CH2)3OH
Secondary alcohols
propan-2-ol (CH3)2CHOH
2-butanol, butan-2-ol, sec-butanol, sec-butyl alcohol, CH3CHOHCH2CH3
Tertiary alcohols
tert butanol, tert-butyl alcohol, 2-methylpropan-2-ol (CH3)3COH, CH3CH3COHCH3, simplest tertiary alcohol
Alcohols, R-OH, are compounds in which a functional group, the hydroxyl group, -OH, is attached to a saturated carbon atom,
e.g. R3COH.
The "hydroxyl" refers to the radical HO-.
The "alcohol" in alcoholic beverages is ethanol, ethyl alcohol, CH3CH2OH.
Alkanol, CnH2n+2O
Alcohol Ethanol safety
Do not heat ethanol over an open flame but use a water bath.
However, ethanol may be use in small quantities in alcohol burners to measure heat of combustion and for reaction with alkanoic acids
to form esters.
Ethanol forms violently explosive mixtures with nitric acid and other oxidizing agents.
Ethanol with acidified dichromate solutions is highly exothermic.
Ethanol reacts violently with potassium.
Alcohol flammability, ethanol > 70% (PG II), < 70% (e.g. 24%) (PG III), < 24% not classified as "dangerous goods"

16.1.3a Propanol (C3H7OH)
Two isomers:
1. Propan-1-ol, 1-propanol (n-propyl alcohol) (CH3CH2CH2OH), Highly flammable, Toxic if ingested
2. Propan-2-ol, 2-propanol (iso-propyl alcohol) (CH3CH(OH)CH3), C3H7OH, sec-propyl alcohol, rubbing alcohol, Flammable
Potassium dichromate as an oxidizing agent, propan-2-ol (isopropanol) --> propanone (acetone) + water: 15.2.3, (See: 5.)

16.1.3b Butanol (C4H9OH)
Butanol, butyl alcohol (C4H9OH) has 4 isomers:
("Butanol" may refer to either butan-1-ol or butan-2-ol.)
1. Butan-1-ol, n-butanol, 1-butanol, n-butyl alcohol, butyl alcohol, (primary alcohol), CH3(CH2)3OH (C4H9OH), n-propyl carbinol,
(biobutanol), product of carbohydrate fermentation, common flavourant
2. Butan-2-ol, sec-butanol, 2-butanol, sec-butyl alcohol (secondary alcohol) CH3CH(OH)C2H5 (C4H9OH), secondary butanol,
secondary butyl alcohol, s-butyl alcohol, product of grain and hops fermentation
3. isobutanol, isobutyl alcohol, IBA (CH3)2CHCH2OH, (C4H9OH), 2-methylpropan-1-ol, 2-methyl-1-propanol, additive to reduce
viscosity, flavouring agent
4. tert-butanol, t-butanol, tert-butyl alcohol (CH3)3COH, C4H10O, 2-methypropan-2-ol, 2-methyl-1-propanol, trimethyl carbinol,
(simplest tertiary alcohol, so is often just called "butyl alcohol" or "butanol", with the hydroxyl on the same carbon with three methyl
groups.), paint remover, solvent, Harmful by all routes, flammable

16.1.3c Butyl glycol (C4H9OCH2CH2OH)
2-butoxyethanol, butyl cellosolve, C4H9OCH2CH2OH, butyl ether of ethylene glycol, pH 11, in window cleaner "Windex", inks, paint
solvents 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), b.p. 197.5oC, car
radiator antifreeze, coolant, in hydraulic fluids, paint and plastic solvent, sweet taste but poisonous
2. Butane-1, 4-diol, C4H10O2, [HO(CH2]4OH], tetramethylene glycol
CH2CH2 (oxidation) --> CH2OCH2 (+ water) --> HOCH2CH2CH2CH2OH
ethene (oxidation) --> epoxyethane (+ water) --> ethane-1.2-diol (glycol, antifreeze)
3. Propane-1, 2 diol, propylene glycol, C3H8O2, CH3CHOHCH2OH, colourless, tasteless, odourless, solvent for pharmaceutical
preparations Trihydric alcohols, glycerol
The trihydric alcohols, have three hydroxyl groups on different carbon atoms, e.g. 1.2, 3-trihydoxypropane, glycerol
[HOCH2CH(OH)CH2OH] Nitroglycerine
Nitroglycerine (UK), Nitroglycerin (USA)
glycerol + cold mixture of concentrated sulfuric acid + nitric acid --> CH2(NO3)CH(NO3)CH2(NO3), C3H5(ONO2)3, C3H5N3O9,
nitroglycerine, ester of nitric acid
Nitroglycerine is a colourless, insoluble oil, solidifies on cooling, contact explosive, used to make dynamite and cordite.
Dynamite is nitroglycerine surrounded by a ring of diatomite, diatomaceous earth, kieselgur, SiO2Al2O3Fe2O3.
Cordite is a smokeless explosive powder, shaped as cords, e.g. gun cotton + nitroglycerine + petroleum jelly
Nitroglycerine is a very unstable liquid that explodes if given a slight shock.
It freezes at 13oC, but is more likely to explode if solid.
It is used to make safer explosives, e.g. dynamite.
It is also used in very small tablets for the heart condition angina pectoris where people get out of breath and suffer pain in the chest
from over-exertion. 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. Alcohols, primary, secondary and tertiary aliphatic alcohols
Primary alcohols RCH2OH, Secondary alcohols R2CHOH, Tertiary alcohols R3COH
See 3.38: Carbon dioxide and fermentation for brewing
See 16.5.10: Rubbing alcohol, surgical spirit Tests for alcohols, potassium manganate (VII)

Primary alcohols
Primary alcohols, e.g. methanol (methyl alcohol, CH3OH), propanol (isomer propan-1-ol, n-propyl alcohol, CH3CH2CH2OH),
and butan-1-ol (1-butanol, n-butanol, CH3(CH2)3OH), have two hydrogen atoms attached to the carbon atom attached to the
hydroxyl group (-OH).
So they all have -CH2OH in their molecules.
They can be directly oxidized to aldehydes or carboxylic acids using oxidizing agents.
(O)R1-CH(OH)-R2 --> R1-C(O)-R2(O)R-CH2OH --> R-CHO(O)R-CHO --> R-COOH
1.1 Allyl alcohol, CH2:CHCH2OH, prop-2-en-1-ol, 2-propen-1-ol, Highly toxic by all routes

Secondary alcohols
Secondary alcohols, e.g. propan-2-ol (CH3)2CHOH, rubbing alcohol, isopropyl alcohol and secondary butyl alcohol, butan-2-ol
(CH3CH2CH[CH3]OH), [ or CH3CH(OH)C2H5], have one hydrogen atom attached to the carbon atom attached to the hydroxyl
group (-OH).
So they all have (-CHOH), in their molecules.
They can be slowly oxidized to ketones.
(O)R1-CH(OH)-R2 --> R1-C(O)-R2
Isopropanol, isopropyl alcohol

Tertiary alcohols
Tertiary alcohols, e.g. 2-methylpropan-2-ol, 2-methyl-2-propanol (CH3)3COH, tertiary butyl alcohol has no hydrogen atom
attached to the carbon atom attached to the -OH group.
So they all have -COH in their molecules. Tests for alcohols, potassium manganate (VII)
Tests for primary, secondary and tertiary aliphatic alcohols
To one drop of each alcohol in three test-tubes, add saturated potassium manganate (VII) solution drop by drop with shaking.
If decolorization occurs, continue adding drops until pink colouration persists, as shown by spot testing on filter paper.
Add one drop of concentrated sulfuric acid and resume adding potassium manganate (VII) drop by drop.
No decolorization occurs with tertiary alcohols.
The colour eventually fades with secondary alcohols, but persists with primary alcohols. Prepare sodium ethoxide
Sodium ethoxide is the salt of a weak acid, ethanoic acid, and a strong base, sodium hydroxide.
Add a pinhead size piece of sodium to 1 mL of ethyl alcohol.
Tests for hydrogen gas:
Na (s) + 2C2H5OH (l) --> 2C2H5ONa (s) + H2 (g)
sodium + ethanol --> sodium ethoxide + hydrogen
Evaporate the sodium ethoxide solution to form white crystals.
Add drops of water and tests for litmus that turns blue. Phenols
Phenols, group: (OH-C), in a benzene ring, Phenol = (C6H5O6)
| See diagram Phenols, quinones, naphthols, coniferyl alcohol (p-coumaryl alcohol), urushiol, organohalogens
| See diagram Phenols, quinones
| Antioxidant phenols, antioxidants, vitamin E, beta carotene
| Cholesterol, C27H46O
1. Phenols, Ar-OH, are compounds with an hydroxyl group, -OH, firmly attached to an aromatic ring, e.g. benzene, 2-naphthol,
benzene-OH, hydroxybenzenes
Phenols, group: (OH-C), in a benzene ring, Phenol = (C6H5O6):
Phenols (hydroxyl group -OH), connected to a carbon atom in a benzene ring, benzene-OH, hydroxybenzenes
The -OH is so firmly attached that the O-H bond tends to break to lose an H+ ion to form a weak acid.
2. Phenols divided into mono-, di-, tri- tetra-, and polyhydric phenols, e.g. p-chlorophenol, C6H4ClOH, 2, 4, 6-tribromophenol,
Chlorophenol red, C19H12Cl2O5S, (acid-base indicator): 8.0
PLA synthetic fibre, polylactic acid, polylactide Pyrogallol
Pyrogallol, C6H3(OH)3, 1.2, 3-trihydroxybenzene, white crystals, reducing agent, alkaline solution (use sodium
hydrogen carbonate not sodium hydroxide), reacts with oxygen in the air to form a brown polymer.
Pyrogallol is used in experiments where oxygen must be eliminated from a gas or from the air.
Pyrogallol is prepared by heating gallic acid, C6H2(OH)3COOH, (3, 4, 5-trihydroxybenzoic acid). Naphthols
See diagram Phenols, Quinones, naphthols | See Tests for carbonates, Molisch's test (α-naphthol test)
1-naphthol, C10H7OH, a-naphthol, α-naphthol, naphthalen-1-ol, tests for carbonates
2-naphthol, C10H7OH, b-naphthol, beta-naphthol, naphthalen-2-ol, white solid, antioxidant in rubber products, antiseptic, tests for
primary amines Cresols
See Cresylic acid, CH3C6H4OH, "cresol (mixture of the three isomers of cresol)"
Cresols are methyl phenols, C7H8O, CH3C6H4OH, produced from coal tar creosote or by methylation of phenol
"Cresol" used as a disinfectant is usually a cresol mixture: o-cresol, m-cresol, p-cresol.
Toxic by all routes
Cresol isomers:
(o-Cresol, ortho-cresol, 2-Methylphenol), colourless crystals
(m-Cresol, meta-cresol, 3-Methylphenol), liquid
(p-Cresol, para-cresol, 4-Methylphenol), solid Resorcinol
See diagram Resorcinol
Resorcinol, C6H4(OH)2, [benzene-1, 3-diol] is a dihydric phenol used with formaldehyde (methanal, HCHO)
Resorcinol, crystals, resorcin, m-dihydroxybenzene, 1.3-dihydroxybenzene, benzene-1-3-diol, benzene-1-3-diol,
1.3 benzenediol (a dihydroxy phenol)
Resorcinol is harmful, corrosive to skin.
Resorcinol, Solution <10%, Not hazardous, but do not ingest
Resorcinol (test reagent in ethanol), explosive with nitric acid, turns red in light, antiseptic, colourless crystals, used for cold-setting
adhesives with formaldehyde, also used to make plasticizers, resins and fluorescein dyes.
Resorcinol, C6H6O2, argan oil, in Argania spinosa.
Prepare formaldehyde resorcinol resin:
Resorcinol, Xanthene dyes: Triclosan
See diagram Triclosan
Triclosan, 5-chloro-2-(2, 4-dichlorophenoxy) phenol, C12H7Cl3O2, is an organohalogen polychlorophenoxy phenol used in
anti-bacterial and anti-fungal products, and in low concentrations in many other products, including toothpaste, mouthwash, deodorants,
soap, scent, detergent dishwashing liquid, hand washes, at high concentrations is harmful by inhalation, irritant, environmental danger
Triclosan is suspected of causing bacterial resistance because of it widespread use and occurrence in the environment and may weaken
the immune system.
Other organohalogens include: 2, 4, 6-trichlorophenol, 2, 4, 6-tribromianisole, 2, 4, 6-trichloroanisole, chlorophenol compounds +
filamentous fungi --> 2, 4, 6-trichloroanisole. Thiols (Mercaptans)
See diagram Thiophenol (phenyl mercaptan), | See diagram 16.13.10: Metam, zineb
Thiols (mercaptans), thio alcohols, Thioalcohols group: (-SH), Suffix: (-thiol) (SH in an organic compound)
Thiols, thio-alcohols (RSH, R not equal to H) (sulfhydryl group: -SH, characteristic of thiols).
(Suffix: -thiol), [old name: mercaptans, because react with mercuric ion to produce mercaptides (RS)2Hg], e.g. methanethiol, methyl
mercaptan (CH3SH), ethanethiol (MeCH2SH), ethyl mercaptan (ethanethiol or ethan-ethiol or captan) (C2H5SH), 1-butanethiol,
n-butyl-mercaptan (CH3CH2CH2CH2SH), thiophenol, phenyl mercaptan Ph-SH, sodium thiolate: (RS-Na+)
Thiols, RS-H, are oxidized to disulfides, RS-SR. Methanethiol from asparagus
The methylmethionine and asparagusic acid, α-aminodimethyl-γ-butyrothetin, in asparagus may produce malodorous methanethiol,
dimethyl disulfide and dimethyl sulfone in people who eat asparagus.
However, less than 50% of adults can smell these compounds in the urine.
Family studies suggest that the ability to produce the odorous urine is inherited as an autosomal dominant trait. Methyl mercaptan
Methyl mercaptan, methanethiol, CH3SH (MeSH), colourless gas, very flammable, offensive rotten cabbage or
decomposing vegetables smell in bad breath and flatus, in some nuts and cheese Allyl mercaptan
Allyl mercaptan, flavouring agent, 2-propene-1-thiol, from garlic, C3H6S, EC Number (EINECS): 870-23-5
Odour threshold value: 6 × 107 molecules / mL of air Ethyl mercaptan
Ethyl mercaptan, ethanethiol, CH3CH2SH, colourless gas, offensive rotten cabbage smell, poisonous and used as
oderant in LPG gas at less than poisonous concentration to allow early detection of gas leaks
There is some evidence that very old men cannot smell it and so are susceptible to LPG gas poisoning. Thiophene
Thiophene, thiolane, THT (CH2)4S, tetrahydrothiophene, colourless, unpleasant odour gas, used as odorant in natural gas and LPG
gas (not in USA) Phenothiazine, PTZ, C12H9NS
11.12.1 Tranquillizers 1, major tranquillizers
See diagram: 14.05, Phenothiazine, S(C6H4)2NH
Phenothiazine, light green powder turns green-blue in sunlight, psychoactive drug, antiemetic, antihistaminic, anticholinergic, prevents
emesis. Ethers
1.13 Ethers, List of ethers
Ethers have two hydrocarbon groups linked by one oxygen, and have compounds in the form: R1OR2 (R not equal to H), where R1
may or may not be the same as R2, e.g. the anaesthetic diethyl ether.
Ethers (ROR') (CnH2n+2O), alkyl ethers, ethoxyethane ether, e.g. dimethyl ether (CH3OCH3) Ethyl cellulose
Ethyl cellulose, C20H38O11, cellulose ethyl ether, "Aquacoat", food additive emulsifier E462, prepared from cellulose in wood and
chemically ethylated (i.e. some hydroxyl groups converted to ethyl ether groups), food stabilizer and thickening agent, filler, dietary fibre,
anti-clumping agent, emulsifier.
Ethyl cellulose is no longer permitted as emulsifier in the EU, because it can be fermented in the large intestine to cause bloating,
constipation and diarrhoea. Acetates
Acetates (ethanoates), ROAc, salt or ester of ethanoic acid (acetic acid)
As a salt: sodium acetate, sodium ethanoate (CH3COONa).
As an ester: ethyl ethanoate (CH3COOC2H5) Benzoyl
Benzoyl group, benzene carbonyl group C6H5CO-, e.g. benzoyl chloride (C6H5COCl) Acetal
Acetal (alcohol + aldehyde), RCH(OR')2, where R and R' = organic radicals and R may be hydrogen
Acetal, 1.1-diethoxy ethane, CH3CH(OC2H5)2, is a colourless flammable solvent, smelly liquid
It is formed by reaction of acetaldehyde with ethanol.
Hemiacetals: [RCH(OH)R'], Di-methyl acetals: [RC(OMe)2R'], Di-ethyl acetals: [RC(OEt)2R'] (polyacetals, polyoxymethylene resin,
POM) Salts
Salts, e.g. sodium ethanoate (sodium acetate) (CH3COONa), ammonium acetate (CH3COONH4)
NaHCO3 + CH3COOH --> CH3COONa + H2O + CO2 (g) Saturated hydrocarbons, e.g. hexane, C6H14
All carbon atoms in the compound have either four or three hydrogens bonded to them and no double bonds, triple bonds or rings.
They react in almost the same way, as in ignition test and bromine water test. Tests for unsaturated hydrocarbons, bromine water tests for unsaturation Tests for unsaturated hydrocarbons, ignition tests for unsaturation Acyl halide
Acyl halide, acid chloride, Acid chlorides group: (-COCL), Suffix: -oyl chloride
Acyl chloride (RCOCl), e.g. ethanoyl chloride (acetyl chloride, CH3COCl) Amides
Amides, acid amides (-amide) (amide group: -CONH2, RCONH2), Suffix: -amide, e.g. urea (H2NC=ONH2)
[IUPAC: Do NOT distinguish amides with NH2, NHR, NR2 groups by the terms "primary, secondary, tertiary".]
1. Primary amides RCONH2, e.g. alkanamides: ethanamide (acetamide), (CH3CONH2) propanamide (C2H5CONH2)
2. Secondary amides, N-substituted amides RCONHR'
3. Tertiary amides RCNR'R"
Secondary or tertiary amides have the prefix N, e.g. N-ethylethanamide CH3CONHCH2CH3,
N.N-dimethylmethanamide HCON(CH3)2 (the polymer group -CO-NH-) (inorganic amides, e.g. KNH2) Carbamates
See diagram 16.13.7: Carbamates, carbaryl, methiocarb
Carbamates are derivatives of carbamic acid, NH2COOH.
Urethanes are esters of carbamic acid, i.e. alkyl carbamates.
Examples of carbamates: carbamic acid, ammonium carbamate, bendiocarb, carbaryl, oxamyl, propoxur, urethane.
Combustion of carbamates may produce noxious NOx and carbon monoxide.
Carbamates are more reactive than amides and can form polyurethane resins.
Carbamates are incompatible with strong acids and bases, strong oxidizing acids, and peroxides.
Many carbamates are used as pesticides because of their anticholinesterase activity, e.g. carbaryl, propoxur, bendiocarb and methomyl. Acrylamide
Acrylamide, C3H5NO, 2-propenamide, ethylene carboxamide, acrylic amide, propenoic acid, UN 2074, vinyl amide, is toxic if ingested,
crystalline form and aqueous solutions, monomer or polymer.
Acrylamide, C3H5NO, CH2CHCONH2, is the amide of acrylic acid, propenoic acid (CH2CHCOOH), an unsaturated liquid
carboxylic acid.
Acrylamide is a poison, harmful if swallowed, inhaled or absorbed through skin, affects central and peripheral nervous systems and
reproductive system.
It causes irritation to skin, eyes and respiratory tract, suspected cancer hazard depending on level and duration of exposure, possible
birth defect hazard.
It is thermally unstable, but can polymerize explosively if heated to the melting point.
It is most common in overcooked French fries and potato chips, also burned toast and burned high carbohydrate foods.
The European Food Safety Authority (EFSA) recommends consuming golden rather than dark brown or black toast, short espresso
rather than lungo, and avoiding overcooked foods.
Acrylamide is a toxic chemical which could cause tumours.
It is not deliberately added to food by manufacturers, it is a by-product of the cooking process and has always been around.
A lot of research has been done into the chemical's effect on humans, first highlighted as a potential risk in a 2002 Swedish study.
In 2015, the European Food Standard Agency (EFSA) published its first full risk assessment of acrylamide in food, which found that the
chemical potentially increases the risk of cancer for all age groups.
The FSA explain: "This means that acrylamide might contribute to your lifetime risk of developing cancer, although it is not possible to
estimate how big this contribution may be.
Eating too much processed and red meat, and cooking meat at high temperatures on grills and BBQs, could also increase your cancer risk.
"Coffee has been shown, over and over again, to be a healthy beverage," said William Murray, president and chief executive of the National
Coffee Association, in reaction to the decision.
A previous case resulted in potato-chip makers agreeing in 2008 to pay $3 million and remove acrylamide from their products.
The chip-makers opted to do that rather than post cancer warnings like those that are found, and largely ignored, throughout California.
He argued the lawsuit "does nothing to improve public health."
Kathryn M. Wilson, a cancer epidemiologist at Harvard University, told the LA Times: "I think the evidence that acrylamide makes a difference
for human cancer risk is pretty weak."
31/3/2018 LOS ANGELES
A Los Angeles judge determined that coffee companies must carry a cancer warning label because of a chemical produced in the roasting process.
The judge said Wednesday that Starbucks and other companies failed to show that benefits from drinking coffee outweighed any risks.
He ruled in an earlier phase of trial that companies had not shown the threat from the chemical was insignificant.
The Council for Education and Research on Toxics, a nonprofit group, sued Starbucks and 90 other companies under a state law that requires
warnings on a wide range of chemicals that can cause cancer, including acrylamide, a carcinogen present in coffee. Acid anhydrides
Acid anhydrides, acyl anhydrides, anhydrides [RCO-O-COR' (R(C=O)O(C=O)R')], e.g. ethanoic anhydride (acetic anhydride),
[(CH3CO)2O], ethanoic anhydride [CH3(C=O)O(C=O)CH3], trifluoroethanoic propanoic anhydride [CH3CH2(C=O)O(C=O)CF3] Imides
Imides (R1CO-NH-COR2) (imido group: -CONHCO-), e.g. gluthemide (C13H15NO2).
The polymer group (-CO-NR-CO), polyimides, N-(trichloromethylthio), cyclohex-4-ene-1,2-dicarboyimide

16.1.12 Fractional distillation of crude oil
A fractionating column is used to separate the distillates that boil within a temperature range, i.e. the "fractions".
Fractional distillation of crude oil: petroleum gas (LPG), naphtha, petrol (gasoline), kerosene (paraffin oil), diesel oil, lubricating oil
(motor oil), paraffin wax (fuel oil), residuals (bitumen, "tar", asphalt, waxes).

The word "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.

Mineral oil
Mineral oil, low value byproduct of petroleum distillation, usually 15o C to 40o C, many uses, lubricating light oil.

Hydraulic fluid
Hydraulic fluid, mineral oil with low compressibility, needs correct viscosity for different machines Petroleum gas
Petroleum gas (methane, ethane, propane, butane), Mix of 1 to 4 carbon atoms, boiling range < 40oC.
Liquefied under pressure as LPG (liquefied petroleum gas), a mixture mainly of propane (C3H8), and butane (C4H10). Naphtha
Naphtha (petroleum naphtha, ligroin), processed to make gasoline
Mix of 5 to 9 carbon atoms, mainly aliphatic, e.g. alkanes, boiling range 120oC to 180oC, or < 200oC.
The light hydrocarbon cut between gasoline and kerosene.
(Another naphtha can also be produced from coal tar.) Petrol
Petrol, "gas", gasoline, motor fuel
Mix of C6H14 to C11H24, 5 to 12 carbon atoms, alkanes and cycloalkanes, boiling range 40 to 205oC Kerosene
Kerosene, kerosine, paraffin oil, jet engine fuel, tractor fuel
Mix of C12H26 to C15H32, 10 to 18 carbon atoms, alkanes and aromatics, boiling range 175oC to 325oC Diesel oil
Diesel oil, gas oil or diesel distillate, diesel fuel, heating oil
Mix of C15H32 to C18H38, 12 or more carbon atoms, alkanes, boiling range 250oC to 350oC Lubricating oil
Lubricating oil, motor oil, grease
Mix of C16H34 to C24H50, 20 to 50 carbon atoms, alkanes and cycloalkanes and aromatics, boiling range 300oC to 370oC Paraffin wax
Paraffin wax, heavy gas, fuel oil
Mix of C20H42 and higher hydrocarbons, 20 to 70 carbon atoms, alkanes and cycloalkanes and aromatics, boiling range 370oC to
600oC Residuals
Residuals, bitumen, "tar", asphalt, waxes
A mix of C24H50 and higher hydrocarbons, multiple-ringed compounds, 70 or more carbon atoms, boiling range > 600oC
Petroleum jelly is a saturated semi-solid of crystalline and liquid hydrocarbons, carbon numbers < C25, made by dewaxing paraffinic
residual oil.
Naphtha, "Greek fire", was an inflammable bituminous substance used in warfare.

16.1.13 Prepare triodomethane (iodoform)
See 1.6: Iodine solution, tests for starch | See diagram 16.2.2: Halogen compounds, haloalkanes
Add five drops of iodine solution to five drops of ethanol.
Add drops of dilute sodium hydroxide solution until the brown colour of iodine disappears.
Observe the crystals under a microscope.
C2H5OH + 4I2 + 6NaOH --> HCOONa + 5NaI + 5H2O + CHI3
ethanol + iodine + sodium hydroxide --> sodium methanoate (sodium formate) + sodium iodide + water + triodomethane (iodoform)

16.1.14 Prepare trichloromethane (chloroform)
Trichloromethane, CHCl3, chloroform
See diagram 16.1.7: Prepare chloroform | See 16.2.2: Chlorinated hydrocarbons, haloalkanes
Bleaching powder is usually a mixture of calcium chlorate (I) [basic calcium chloride, calcium hypochlorite], calcium chloride and
calcium hydroxide prepared by passing chlorine gas through a calcium hydroxide solution.
Calcium chlorate (I) oxidizes ethanol to ethyl aldehyde.
Aldehydes or ketones have a hydrogen atom attached to the carbon atom attached to the carbonyl group, C=O.
This hydrogen atom can be replaced by a halogen atom to form halogen compounds.
If a molecule contains three such hydrogen atoms, e.g. ethanol and propanone (acetone) molecule, a trihalide may be formed,
e.g. trichloromethane (chloroform, CCl3).
H3C-C(O)-R + 3OX --> X3C-C(O)-R
ketone or aldehyde hypochlorite --> trihalide
The trihalide decomposes in a basic solution to a haloform (CHX3), e.g. CHCl3C-C(O)-R (l) + OH- (aq) --> CHCl3 (l) + RCOO- (aq) Reaction of acetone with bleaching powder
CH3COCH3 + 3Cl2 --> CCl3COCH3 + 3HCl
2CCl3COCH3 + Ca(OH)2 --> 2CHCl3 + (CH3COO)2Ca
Ca(OH)2 + 2HCl --> CaCl2 + 2H2O Reaction of ethyl alcohol with bleaching powder
C2H5OH (l) + Cl2 (g) --> CH3CHO (l) + 2HCl (aq)
ethyl alcohol + chlorine --> ethyl aldehyde
CH3CHO (l) + 3Cl2 (g) --> CCl3CHO (l) + 3HCl (aq)
2CCl3CHO (l) + Ca(OH)2 (aq) --> 2CHCl3 (l) + (HCOO)2Ca (aq)
Be careful! Do not allow any flames in the laboratory!
Grind together in a mortar and pestle 5 g bleaching powder and 10 mL water.
Put the mixture into the test-tube of the gas preparation apparatus.
Cool the test-tube.
Add either 4 mL ethanol in 2 mL water or 4 mL propanone (acetone) in 2 mL of water.
Swirl the contents of the test-tube and keep it cool.
Use an electric water bath to warm the temperature to 55oC.
Water and trichloromethane condense in the receiving test-tube leaving a calcium salt solution in the test-tube.
Add water to the distillate and separate the trichloromethane with a separating funnel.

16.2.3 Organometal compounds
(prefix the metal with organo-), e.g. organomagnesium compounds.
MeMgI iodo(methyl)magnesium, Et2Mg diethylmagnesium Carbides, C4-
Carbide are binary compounds of:
1. C + electropositive element, e.g. calcium carbide.
2. C + heavy metal for cutting tools, e.g. aluminium carbide (Al4C3), chromium carbide, Cr3C2, iron carbide Fe3C (cementite).
Tungsten carbide ("carbide", WC), is used for cutting tools, milling tools, abrasives, jewellery.
Iron carbide is formed with carbon monoxide when iron oxide is heated with charcoal.
3Fe2O3 +11C --> 2Fe3C + 9CO (g)

Types of carbides
1. Methanides
Methanides, e.g. aluminium carbide, Al4C3
Hydrocarbyl anions, methyl anion, conjugate base of methane
Methanides + water --> methane, e.g. aluminium carbide (Al4C3)

2. Acetylides
Acetylides, salts of acetylide anion C22- (percarbide)
Formed by alkali metals, alkaline earth metals, lanthanoid metals, e.g. sodium carbide Na2C2, copper (I) acetylide Cu2C2,
lanthanum carbide LaC2, aluminium carbide Al4C3, calcium acetylide CaC2, cementite Fe3C (iron carbide), copper (I) acetylide
Acetylides (percarbides, C22-) + water --> acetylene, e.g. Na2C2, CaC2
Calcium carbide CaC2 (calcium dicarbide, "carbide", calcium acetylide, acetylenogen, ethnide dicarbide, Toxic by all routes
CaC2 + 2H2O --> C2H2 + Ca(OH)2
calcium carbide + water --> acetylene + calcium hydroxide

3. Sesquicarbides, C34-, e.g. Mg2C3

4. Covalent carbides
Covalent carbides, e.g. boron carbide B4C, silicon carbide, SiC (carborundum)
See: Models, (Commercial)
Silicon carbide, SiC, carborundum, abrasive, moissanite synthetic gemstone, emery paper, sanding paper, sharpening stone, fine
particles, Toxic by inhalation

16.2.4 Nitrogen compounds, one atom of nitrogen
See Amides Nitriles
Nitriles (acid nitriles, alkyl cyanides, cyanides) (-CN, R-C triple bond N) (note triple bond), Cyanide ion: CN- e.g. ethane nitrile,
Ascetonitrile (methyl cyanide, ) (CH3CN),
5-methoxyhexanenitrile, [CH3C(OCH3)HCH2CH2CH2CN],
Acrylonitrile for making Orlon (vinyl cyanide, 1-cyanoethene) (CH2=CH-CN) Cyanamides
Cyanamides (inorganic, CN22-), ionization reaction of methylamine
See diagram Melamine
cyanic acid (fulminic acid) (HOCCN) (cyanates, fulminates), Isocyanic acid (H-N=C=O), isocyanates
(isocyanate group: -NCO, HN=C=O), isocyanides (HNC), hydrocyanic acid (HCN)
CaCn2 + H2O + CO2 --> H2NCN + CaCO3
calcium cyanamide + water + carbon dioxide --> cyanamide + calcium carbonate
(NH2)2CO --> HCNO + NH3
urea --> cyanic acid + ammonia
6HCNO --> C3H6N6 + 3CO2 (polymerization reaction)
cyanic acid --> melamine + carbon dioxide
6(NH2)CO --> C3H6N6 + 6NH3 + 3CO2
Melamine, C3H6N6, 2, 4, 6-triamino-1.3, 5-triazine is 66% nitrogen w/w and is used in the plastics industry.
Unfortunately, its high nitrogen content has been the reason for its use as a powdered milk pollutant in China resulting in death and
kidney problems in young babies due to the formation of kidney stones.
Melamine-formaldehyde (MF), C4H6N6O, hard to ignite, alkaline fumes, burns with pale yellow flame (light blue-green edge),
formaldehyde and fish-like smell, thermosetting plastic, retains strength and shape on heating
Melamine crockery is sold as being green, virtually unbreakable, dishwasher safe, Not suitable for microwave oven, plate, 18 mm diameter Amines
Amines, aliphatic amines (RNH2-, R = alkyl group), ionization reaction of methylamine
Amines have lower boiling temperatures than alcohols.
Methylamine and ethylamine are gases at room temperature.
Longer chain amines are volatile liquids with rotten fishy smells characteristic of decomposing proteins
Amines are bases (can accept a H+ ion), so can react with acids to form salts and lose the fishy smell.
1. Primary amines: R-NH2
NH2- = amino group, e.g. methylamine (CH3-NH2), ethylamine (CH3CH2-NH2).
Aniline, C6H5NH2, phenylamine
2. Secondary amines: R2-NH
NH = imino group, e.g. dimethylamine (CH3)2NH
3. Tertiary amines: R3-N
N = nitrogen, e.g.
Triethylamine, C6H15N
Trimethylamine, C3H9N
Physostigmine, C15H21N3O2, tertiary amine Methylamine ionization reaction
CH3NH2 + H2O <--> CH3NH3+ + OH-
methylamine + water <--> methylammonium ion + hydroxide ion Prepare phenylamine
1. Benzene + concentrated nitric acid + concentrated sulfuric acid --> nitrobenzene, C6H5NO2
2. Nitrobenzene + tin catalyst Sn + reducing agent hydrochloric acid --> phenylamine + water
C6H5NO2 + 6 H+ --> C6H5NH2 + 2H2O Nitrosamines
Nitrosamines are produced by reaction of nitrous acid with secondary amines.
They can be formed in the gut when nitrites react with amino acids.
C4 explosive, H8N8O8, HMX, Octogen, detonator, solid rocket propellant, mainly cyclonite or cyclotrimethylene trinitramine
RDX explosive (Research Department Explosive, C3H6N6O6, Cyclonite, Hexagen, used against German submarines during World
War II Nitramine
Nitramine (acid-base indicator, 3.5), C7H5N5O8, tetryl, colourless-yellow crystals, explosive formerly used in munitions Clenbuterol, C12H18Cl2N2O
Performancing-enhancing drug banned by the International Olympic Committee.
It is illegally used to build skeletal muscle and increase metabolism, but may cause heart attacks.
Clenbuterol is a substituted phenylaminoethanol that has beta-2 adrenomimetic properties at very low doses.
It is used as a bronchodilator in asthma.
Although approved for use in some countries, as 2006 clenbuterol is not an ingredient of any therapeutic drug approved by the US
Food and Drug Administration. Ethylenediamine
ClCH2CH2Cl + 4 NH3 --> H2NCH2CH2NH2 + 2 NH4Cl
1.2-dichloroethane + ammonia --> ethylenediamine + ammonium chloride Imines
Imines, R2C=NR', Imino group = ring containing (-NH-), or (=NH), linked to C] (RN=CR', where R = H or hydrocarbyl,
e.g. (ethyl-), O-benzoquinonedimine
Imine primary RC(=NH)R (imino-) (-imine)
Imine secondary RCH=NR (imino-) (-imine) Cyclic imines
Pyrroline, C4H7N, 1-Pyrroline
Acetylpyrroline">Acetyl pyrroline, C6H9NO Nitroalkanes
Nitroalkanes (nitroparaffins) (CnH2n+1NO2)
Nitromethane (CH3NO2), nitroethane, urea (carbamide) Nitrites
(NO2-), dioxonitrate ion, salts or esters of nitrous acid, (O=NOH),
Nitrites group: -C=N, Suffix: -nitrite, , e.g. sodium nitrite and potassium nitrite used
as meat curing agents Oximes
Oximes (hydrox-imino-alkanes), Formula R1R2C=NOH, where R1= organic side chain and if R2 = hydrogen, aldoxime forms
or if R2 = organic group, ketoxime forms.
(-CNOH group) (ketone or aldehyde + hydroxylamine - water) (RCNOHR'), e.g. ethanal oxime (acetaldehyde oxime, AAO),
(CH3CH=NOH) Cyanocrylates
Cyanocrylates [(CH2)C(CN)COOR], e.g. "Superglue": Me or Et ester
Ethyl cyanoacrylate, "Superglue", BE CAREFUL! Do not squirt in the eye! Toxic by all routes.
Chemical suppliers: Ethyl 2-cyanoacrylate, liquid, C6H7NO2
GBL, γ-butyrolactone is a naturally occurring colourless oily liquid with a characteristic odour used as a stain remover and stripper,
(including Superglue). Azide compounds
Azide compounds: (N3-), or (-N3), (-N=N+N-), usually attached to carbon, e.g. sodium azide (NaN3), phenyl azide or azidobenzene
(C6H5N3), diazine (diimide) (HN=NH), also, salts of hydrazoic acid, HN3, e.g. sodium azide (NaN3). Azo compounds
Azo compounds: derivatives of diazene (diimide), HN=NH, with both hydrogens substituted by hydrocarbyl groups, e.g. azobenzene
or diphenyldiazene (PhN=NPh).
hydrazone (ketone + hydrazine (N2H4) - water), (RC=NNH2R')
See: 3.0 Benzopurpurin Diazo compounds
Diazonium ion R-N+N, diazonium compounds [(RNN+) Cl-], e.g. diazomethane (CH2=N2)
HNO2 and HCl + R-NH2 --> R-N+N + Cl-
nitrous acid and hydrochloric acid + amines --> diazonium ion + chloride ion
HNO2 + HCl + C6H5NH2 --> C6H5N2Cl + 2H2O
nitrous acid and hydrochloric acid + phenylamine --> benzenediazonium chloride + water
benzenediazonium chloride + phenol --> 4-(phenylazo)phenol + NaCl
benzene-N+NCl- + H-benzene-OH + NaOH --> benzene-N=N-Benzene-OH + NaCl + H2O
4-(phenylazo) phenol is a yellow dye
Azo dyes of the textile industry use diazonium salts.
The material is first soaked in a soluble salt of phenol or naphthol then soaked in a diazonium salt so that the dye forms in the cloth.

16.2.6 Phosphorus compounds
Phosphorous compounds, organophosphorus insecticides
Captan fungicide: 16.6.3
Organophosphorus insecticides (mostly thiophosphates), TEPP (tetraethylpyrophosphate, no longer used as insecticide), parathion,
maldison (Malathion), dimethoate (Rogor), dichlorvos (dimethyl dichlorovinyl phosphate, DDVP, Shelltox strips), demetron (Systox)
See diagram 16.13.6: captan, glyphosate, paraquat
1. Phosphonic acid, phosphorous acid [HPO(OH2), H3PO3]
2. Phosphonoglycine
16.7.3 Glyphosate, herbicide
3. Organic phosphates: acephate, diazinon, dichlorvos, dimethoate, malathion (maldison), naled, parathion Isothiocyanates
Isothiocyanates, R-N=C=S (old name: mustard oil) (RN=C=S), Mustards: [X(CH2.CH2)2S]
Isocyanate group, R-N=C=O --> isothiocyanate group R-N=C=S

Allyl isothiocyanate, C4H5NS
Allyl isothiocyanate, C4H5NS (AITC), CH2CHCH2NCS, oil of mustard, mustard oil, colourless to yellow, oily liquid, irritating
odour, pungent taste, toxic fumes at high temperature, denser than water, slightly soluble in water, fumigant, rubefacient, in cruciferous
vegetables, gives pungent taste of mustard, horseradish, wasabi, apotosis inducer, anti-tumor, anti-oxidant, possibly anti-bladder cancer
in Black mustard | Horseradish | Wasabi

Benzyl isothiocyanate, (BITC), C6H5CH2NCS
Benzyl isothiocyanate (BITC), C6H5CH2NCS, benyl mustard oil, isothiocyanotaometylbenzene, in cruciferous vegetables, possibly
anti-cancer, apotosis, anthelmintic in Papaya seeds
Ethyl isothiocyanate, CH3CH2NCS, ethyl mustard oil
Fluorescein isothiocyanate, (FITC), C21H11NO5S
Methyl isothiocyanate (MITC), CH3NCS, soil fumigant, toxic corrosive, active ingredient in pesticide Metam
Phenethyl isothionate
Phenethyl isothiocyanate (PEITC), C9H9NS, in cruciferous vegetables, watercress, possibly anti-prostate cancer
Phenyl isothiocyanate, C6H5NCS
Phenyl isothiocyanate (PITC), C6H5NCS, Edman's reagent, isothiocyanatobenzene, colourless liquid, pungent odour, used for amino
acids research sequencing peptides
Sulforaphane (sulfurophane), C6H11NOS2, broccoli extract Sulfides
Sulfides: RSR (R not equal to H) (old name: thioethers)
1. People who eat asparagus may notice a malodorous over-boiled cabbage smell in their urine because of sulfur compounds,
e.g. diallyl disulfide, dimethyl sulfide, dimethylsulfone, sulfimides (sulfilimines): (H2S=NH)
2. Diallyl sulfide from boiled cabbage.
3. Disulfides from crushed garlic.

Oil of garlic contains diallyl disulfide, diallyl trisulfide and diallyl tetrasulfide.
When a clove of garlic, Allium sativum, is crushed, the enzyme allinase acts on alliin to produce unstable allicin, which
degrades to diallyl sulfide, and other sulfur compounds.
In distilled oil of garlic, Diallyl Disulfide, can also be prepared by steam distillation.
Allinase is an enzyme active in chopped or crushed garlic.
Alliin + Allinase enzyme --> Allicin (decomposes) --> Diallyl Disulfide.

Alliin, (S-allylcysteine), (3-(Allylsulphinyl)-L-alanine), ACSO, C6H11NO3S, Sulfoxide
may cause respiratory irritation, in fresh garlic produced from Cysteine.

Allicin, C6H10OS2, Sulfoxide
Allicin, Diallyl thiosulfinate, Diallyldisulfid-S-oxid, (Thio-2-propene-1-sulfinic acid S-allyl ester), produce by crushing garlic,
unstable antioxidant, colourless liquid, distinctively pungent smell, botanical anti-fungal agent, antibacterial agent, used to treat
Follicular Lymphoma, in onion, in garlic, in Alliaceae species, causes smell of fresh garlic.
See diagram: Allicin

Diallyl sulfide, Allyl sulfide, Diallylsulfide, Thioallyl ether, C6H10S, organic sulfide.
Di-2-propenyl sulfide, formed by hydrolysis decomposition of cabbage, flavouring ingredient, in animal foods, in Allium species,
in Wasabia japonica (Japanese horseradish), in Brassica nigra (black mustard powder, in cooked beef, possibly anti-cancer.

Diallyl disulfide, C6H10S2, Organic Disulfide
Diallyl disulfide, Allyl disulfide, , in garlic, in Alliaceae species, antineoplastic, antifungal, plant metabolite
health benefits for most people, but some people are allergic to it and most Allium species. Sulfonium compounds
Sulfonium compounds: R3S+, [SR3]+
Sulfonium salts, e.g. trimethylsulfonium chloride [(CH3)3S]+Cl-, Cyclopropyldiphenylsulfonium tetrafluoroborate, C15H15BF4S Thiocyanates Thiocyanates: [RC(=O)SN], Salts and esters of thiocyanic acid, HSCN, e.g. methyl thiocyanate (CH3SCN) Siloxanes
Saturated silicon-oxygen hydrides with chains of alternating silicon and oxygen atoms, e.g. unbranched [H3Si(OSiH2)nOSiH3],
branched [H3Si(OSiH2)nOSiH(OSiH2OSiH3)2].
"Volasil" is octamethylcyclotetrasiloxane.
Dimethylpolysiloxane is an anti-caking agent, emulsifier and anti-foaming agent. Sulfoxide
Sulfoxide, RS(=O)R', contains a sulfinyl, SO, functional group
Alliin, L-alliin, sulfoxide in fresh garlic
Alliin, L-Alliin, C6H11NO3S, ACSO, S-Allyl-L-cysteine sulfoxide, SAC, aroma of Garlic

Dimethyl sulfoxide
Dimethyl sulfoxide, DMSO, [C2H6OS (CH3)2SO)], from wood pulp, oyster garlic taste (irritant, penetrates skin, horse liniment,
anti-inflammatory, paint stripper, colourless, common solvent, gives garlic taste after skin contact
Propanethial- S-oxide, C3H6OS, syn-propanethial S-oxide, a thiocarbonyl S-oxide, lachrymatory factor, in Onion
broken cells --> allinase enzymes + amino acid sulfoxides --> 1-propene sulfenic acid + lachrymotary factor synthesise enzyme -->
syn-Propanethial -S-oxide which stings eyes

16.5.0 Ethanol
Ethanol, ACS reagent, 99.5% (200 proof), absolute, ethyl alcohol, CH3CH2OH, C2H5OH, clear, colourless, mobile liquid, volatile
organic compound, inflammable, pleasant odour, burning taste, miscible with water and most organic solvents, rectified spirit, grain
alcohol, spirit of wine, constant boiling mixture = 95.6% ethanol and 4.4% water, b.p. -78.3oC, absolute alcohol = 100% ethanol, r.d.
0.79 gm cm-3, b.p. 78.5oC, absorbs moisture from air.
Ethyl alcohol becomes very viscous at liquid nitrogen temperatures.
This is known as 'foetal alcohol syndrome'.
Consumption of ethanol during pregnancy may affect the unborn child, resulting in spontaneous abortion, developmental problems, or
birth defects, "foetal alcohol syndrome".
Chronic ingestion of ethanol may cause liver cirrhosis and affect the nervous system.

16.5.1 Methylated spirits
Methylated spirits (95% CH3CH2OH, 5% CH3OH), or absolute ethanol usually denaturated with 4.8% methanol, but composition
may be legally different in different countries, e.g. Australia 2% methanol
Methylated spirits, methylated ethanol, "spirits" (methylated spirits sold retail in Australia as 95% ethanol), UN 1170,
duplicator fluid / spirit, Fordigraph spirit duplicator fluid, spirit vini meth (90% ethanol + 5% v/v methanol, wood alcohol + 5% water),
denatured alcohol, denatured spirits (+ 2% of methyl alcohol, pyridine, + other coal tar unpalatable chemicals) (in UK ethanol + 9.5%
methanol + 0.5% pyridine and a blue dye).
The additional substances "denature" the ethanol so it cannot be consumed, but it may be consumed by Aboriginal people in Australia
by mixing methylated spirits with condensed milk.
Use in illegal home-made alcoholic beverages may cause blindness.
If methylated spirits is swallowed, do NOT induce vomiting, because it may enter the lungs.
Methylated spirit is highly flammable and must not be used near naked flames, e.g. boiled in a beaker set on wire gauze over a Bunsen
burner to extract chlorophyll from leaves.
Do not heat methylated spirit over a Bunsen burner, even in a closed container such as a flask with a reflux condenser, because the
flask may crack.
Methylated spirit burns with a nearly colourless flame so if there is a fire, be careful of the invisible flames.
Use a carbon dioxide fire extinguisher and fire blankets to smother the flames.
Instead, use a water bath to heat methylated spirit in a flask.
Even if the flask cracks, a mixture of water and methylated spirit is much less flammable than pure methylated spirit.
Repeated contact of the skin with methylated spirit can cause dermatitis so wear rubber gloves if using methylated spirit as a solvent for
Do not mix methylated spirit with an oxidizing acid, e.g. concentrated nitric acid, because a vigorous reaction or explosion may occur.
Use methylated spirit as a cheap low toxicity cleaning solvent for solvent extraction.
Observe the rapid changes in colour during the dissolution of plant pigments in methylated spirits.