School Science Lessons
2017-09-14 SP LI
Please send comments to: J.Elfick@uq.edu.au 16 Organic chemistry, tests for organic compounds
Table of contents 188.8.131.52 Acetal 184.108.40.206 Acetates, (ethanoates) 220.127.116.11 Acetylene, C2H2,
ethyne 18.104.22.168 Acid anhydrides 22.214.171.124 Acyl halides 126.96.36.199.1 Acrylamide 188.8.131.52 Acyclic hydrocarbons 16.1.01 Addition reactions 184.108.40.206 Alcohols, phenols, thiols 3.8.0 Alcohols, Fatty alcohols, lauryl
alcohol 220.127.116.11a Alcohol, Ethanol safety 18.104.22.168 Aldehydes 22.214.171.124 Alkaloids from plants 126.96.36.199 Alkanes, (CnH2n+2),
paraffins 188.8.131.52 Alkenes, (CnH2n),
olefins 184.108.40.206 Alkynes, (CnH2n-2),
acetylenes 220.127.116.11 Amides 18.104.22.168.00 Amines 22.214.171.124 Arenes, benzene 126.96.36.199 Benzoyl group Bisphenol-A, (BPA), Epoxy resin
polymer 188.8.131.52a Carbamates 184.108.40.206 Carbides 220.127.116.11 Carboxylic acids and fatty
acids 16.4.1.01 Carbonyls Carvacrol, C10H14O 18.7.23 Chloramines in swimming pools 18.104.22.168.05 Clenbuterol, C12H18Cl2N2O 16.2.10 Coal tar products,
creosote 22.214.171.124.1 Cyanamides, inorganic, (CN22-), 126.96.36.199 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 188.8.131.52 Ethane (C2H6) 184.108.40.206 Ethers, group: (-O-), in organic compound 220.127.116.11 Ethyl cellulose 18.104.22.168 Epoxy resin polymers 22.214.171.124.1 Ethylenediamine 16.6.2 Fixed oils, non-volatile oils 126.96.36.199 Fluorescent liquids 16.1.12 Fractional distillation of crude oil 188.8.131.52 Imides, imido group: (-CONHCO-) 184.108.40.206a Imines, imino group: -NH-, or =NH 220.127.116.11b Cyclic imines 18.104.22.168 Methane, CH4 22.214.171.124
Methyl bromide, bromoethane, CH3Br 126.96.36.199.01 Methylamine ionization reaction 188.8.131.52 Nitrogen compounds, two or more nitrogen
atoms 184.108.40.206.03 Nitrosamines 220.127.116.11.04 Nitramine, (acid-base indicator) 18.104.22.168 Nitriles 22.214.171.124 Nitrites, (NO2-) 126.96.36.199 Nitroalkanes, (nitroparaffins) 16.2.4 Nitrogen compounds, one atom of nitrogen 188.8.131.52 Nitrogen compounds, 2 or more N atoms 16.1.0 Organic chemistry 16.2.3 Organometal compounds 16.1.03 Oxidation reactions, loss of electrons 184.108.40.206 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 220.127.116.11.02 Prepare phenylamine 18.104.22.168 Quinones 16.1.04 Reduction reactions, gain of electrons Ribose, C5H10O5 Ribulose, C5H10O 22.214.171.124 Salts, organic salts, sodium ethanoate 126.96.36.199 Saturated hydrocarbons, hexane, C6H14 188.8.131.52 Sulfur organic compounds 184.108.40.206 Tests for organic compounds 16.6.3 Vegetable oils, Plant oils 220.127.116.11 Acyclic hydrocarbons 18.104.22.168 Acyclic hydrocarbons, alkanes, alkenes 22.214.171.124 Alkanes (CnH2n+2),
paraffins 126.96.36.199 Arenes, benzene 188.8.131.52 Butane (C4H10) 184.108.40.206 Cycloalkanes 220.127.116.11 Ethane (C2H6) 18.104.22.168 Hexane (C6H14) 22.214.171.124 Heptane (C7H16) LPG, (Liquefied Petroleum Gas, LP
gas) 126.96.36.199 Methane, CH4 188.8.131.52 Octane (C8H18),
Octane number 184.108.40.206 Octadecan-1-ol, C18H38O 220.127.116.11 Octanol, CH3(CH2)7OH 18.104.22.168 Pentane (C5H12) 22.214.171.124 Propane (C3H8) 126.96.36.199 Alkanes, (CnH2n+2),
Alkanes, cyclohexane, heptane, hexane, liquefied petroleum gas (LPG),
octane, pentane, petroleum spirit
Alkanes: methane, ethane, propane, butane, pentane, hexane, heptane,
octane, nonane. 188.8.131.52 Alkanes (CnH2n+2),
Alkanes, skeletal formula: See diagram 16.1.1 184.108.40.206 Acyclic hydrocarbons, alkanes, alkenes,
alkynes Iodine value 3.29.0 Collect and weigh the gaseous
products of a burning candle 220.127.116.11 Friedel-Crafts reaction 18.104.22.168 Nitroalkanes, (nitroparaffins),
(CnH2n+1NO2) 22.214.171.124 Oximes (hydrox-imino-alkanes),
Group: (C:NOH) 126.96.36.199 Petroleum gas, (See 188.8.131.52
to 184.108.40.206) 220.127.116.11 Tests for unsaturated alkanes (Experiments) 18.104.22.168 Alkenes, (CnH2n),
22.214.171.124.0 Alkenes, (CnH2n), olefins 126.96.36.199.1 Prepare ethene, (ethylene), C2H4 188.8.131.52.2 Dienes, diolefins 184.108.40.206 Arenes, benzene 220.127.116.11 Arenes, benzene 18.104.22.168.1 Phthalic acid 22.214.171.124 Friedel-Crafts reaction 126.96.36.199 Nitration, (Experiment) 188.8.131.52 Alcohols, phenols,
Alcohols, R-OH, -OH hydroxyl, Prefix: hydroxy-, Suffix: -ol (-OH: alcohol),
(alkanol, alkyl alcohol) 6.6.18 Alcoholic fermentation,
yeast Saccharomyces cerevisiae, (Exp.) 184.108.40.206 Alcohols, phenols, thiols, ethers, epoxy
compounds, acetates (ethanoates), benzoyls, acetals 220.127.116.11.1 Alcohols, primary, secondary
and tertiary aliphatic alcohols 18.104.22.168.1a Tests for alcohols, potassium
manganate (VII) 16.1.3.B Butanol, butyl alcohol,
(C4H9OH) 16.1.3.C Butyl glycol 22.214.171.124.1 Carbolic acid,
phenol, TCP, Dettol 126.96.36.199.3 Cresols 188.8.131.52.1 Dihydric alcohols, glycol 16.5.0 Ethanol 1.4 List of alcohols 16.5.1 Methylated spirits 184.108.40.206.2 Naphthols 220.127.116.11.3 Nitroglycerine (UK),
nitroglycerin (USA) 18.104.22.168.4 Nitrocellulose, gun
cotton 12.12.4 Oxidation of glycerol by
potassium permanganate 22.214.171.124 Phenols, group: (OH-C),
in a benzene ring, Phenol = (C6H5O6) 126.96.36.199 Polyhydric alcohols 4.3.8 Prepare alcohol using immobilized
yeast cells, (Exp.) 188.8.131.52.2 Prepare sodium ethoxide 16.1.3.A Propanol, propyl alcohol, (C3H7OH) 184.108.40.206a Pyrogallol 220.127.116.11.4 Resorcinol 16.1 3.2.5 Triclosan, organohalogens 18.104.22.168.2 Trihydric alcohols, glycerol 22.214.171.124 Thiols, mercaptans, thio alcohols, Thioalcohols
group: (-SH), Suffix: (-thiol), (SH in an organic compound) 16.1.13 Prepare triodomethane,
(iodoform) 16.1.14 Prepare trichloromethane gas, (chloroform) 126.96.36.199 Reaction of acetone with bleaching
powder 188.8.131.52 Reaction of ethyl alcohol with bleaching
powder 184.108.40.206 Carbides 220.127.116.11 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 Asphalt
16.1.12 Fractional distillation of crude oil 18.104.22.168 Petroleum gas, (methane, ethane, propane,
butane), LPG 22.214.171.124 Naphtha, (ligroin), processed to make
gasoline 126.96.36.199 Petrol, "gas", gasoline, motor fuel 188.8.131.52 Kerosene, kerosine, paraffin oil,
jet engine fuel, tractor fuel 184.108.40.206 Diesel oil, gas oil or diesel distillate,
diesel fuel, heating oil 220.127.116.11 Lubricating oil, motor oil, grease 18.104.22.168 Paraffin wax, heavy gas, fuel oil 22.214.171.124 Residuals, bitumen, "tar", asphalt,
waxes, petroleum jelly 126.96.36.199 Nitrogen compounds,
two or more nitrogen atoms 188.8.131.52 Azide compounds 184.108.40.206 Azo compounds 220.127.116.11 Diazo compounds 18.104.22.168 Sulfur organic
Sulfur compounds, (For the "thio" prefix, replace oxygen by sulfur, e.g.
thiobenzamide [PhC(=S)NH2]) 22.214.171.124 Isothiocyanates, R-N=C=S, (old name:
mustard oil), (RN=C=S), Mustards: [X(CH2.CH2)2S] 126.96.36.199 Sulfides Sulfonic acids, group:
R-SO2OH, e.g. methanesulfonic acid, CH3SO2OH,
Salts or esters: sulfonates 188.8.131.52 Sulfonium compounds 184.108.40.206 Thiocyanates: [RC(=O)SN], Salts and
esters of thiocyanic acid, HSCN, e.g. methyl thiocyanate (CH3SCN) 220.127.116.11 Silicones: polymeric
unbranched siloxanes, formula (-OSiR2-)n (R not equal
to H) 18.104.22.168 Siloxanes 22.214.171.124 Sulfoxide 126.96.36.199 Thiols (mercaptans) 188.8.131.52.2 Allyl mercaptan 184.108.40.206.1 Methyl mercaptan 220.127.116.11.3 Ethyl mercaptan, ethanethiol, CH3CH2SH 18.104.22.168.4 Thiophene, thiolane, THT, (CH2)4S 16.1.0 Organic chemistry,
Carbon, C 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
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 22.214.171.124 Methane Methane, CH4,
natural gas 126.96.36.199 Methane, CH4 188.8.131.52 Methane with chlorine, (dangerous) 3.39.1 Methane with steam, (Experiment) 184.108.40.206 Prepare methane gas, (Experiment) 220.127.116.11 Reduce copper oxide with natural gas,
methane, (Experiment) 18.104.22.168 Tests for methane gas, burn methane,
(Experiments) 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
Example: HCl + CH2CH2 --> CH3CH2Cl 16.1.02 Substitution 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
Primary alkanols (alcohols), (-CH2-OH) --> alkanals (aliphatic
Example: CH3OH + O2 --> CH2O + H2
(Pt catalyst) [Oxidation of methanol to methanal using a platinum
Alkanals --> alkanoic acids, e.g. butanoic acid, CH3(CH2)2COOH
Secondary alkanols (alcohols), (CH3)2CHOH -->
alkanones 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). 22.214.171.124 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. 126.96.36.199 Alkanes (CnH2n+2),
The first 10 unbranched alkanes and molecular formula: methane (CH4),
ethane (C2H6), propane (CH3H8),
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-,
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
Saturated hydrocarbons, e.g. hexane, C6H14, all
carbons have either four or three hydrogens bonded to them and no double
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
ethylene + hydrogen --> ethane
CH3CH=CHCH3 + H2 --> CH3CH2CH2CH3
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 188.8.131.52 Cycloalkanes
Cycloalkanes, CnH2n, cycloolefins, cyclanes, polymethylenes,
cycloparaffins, saturated carbon rings.
Cycloalkanes are saturated hydrocarbons with a ring of carbon atoms,
e.g. cyclopropane, C3H6, the simplest cyclobutane,
cyclohexane, cycloheptane, cyclooctane.
The position of branches depends on the alphabetical order of the branch
names so that highest in order is attached to carbon 1,
Cyclopropane, C3H6, colourless gas, anaesthetic,
Cyclobutane, C4H8, (CH2)4,
Cyclopentane, C5H10, Cycloheptane C7H14,
Cyclooctane C8H16 184.108.40.206 Arenes, benzene See 220.127.116.11: 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
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. 18.104.22.168.1 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, widely used as a chemical plasticiser, used to
produce plastics from vinyl
chloride. 3.0.4 Phthalates 22.214.171.124 Nitration See 10.01.10: Liebig condenser
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
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 +
Also, some 1.3-dinitrobenzene may form. 126.96.36.199 Friedel-Crafts
The reaction substitutes a hydrogen atom in an arene ring of a halogenalkane
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 +
CH3Cl +AlCl3 --> CH3+
+ AlCl4- 188.8.131.52 Tests for unsaturated
1. Ignition tests for unsaturation
Ignite a substance in an evaporating basin and observe the smoke over
The darker or more sooty the smoke, the more unsaturated, e.g. aromatic
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 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. 184.108.40.206 Methane, CH4 See diagram 16.0.1: Tetrahedral geometry
of carbon, methane molecule, isobutyl alcohol
Methane is the simplest alkane.
It is colourless and odourless and found in natural gas and bubbles of
methane in swamp water.
Fire damp, which causes explosions in coal mines, is a mixture of methane
Methane is found in large quantities usually associated with petroleum.
It has largely displaced town gas produced from coal.
Methanogenic bacteria live in swamps and in the human gastrointestinal
tract where they liberate methane causing flatulence.
After carbon dioxide, methane produced by bacteria in rice paddies may
be the second most important greenhouse gas made by man.
They produce methane gas anaerobically (without oxygen) by removing the
electrons from hydrogen gas.
The electrons and H+ ions from hydrogen gas are used to reduce
carbon dioxide to methane.
H+ ions combine with the oxygen from carbon dioxide to form
water and electrons move through the steps of an anaerobic electron
transport system to the phosphorylate of ADP to form ATP.
Methane is a simple asphyxiant. 220.127.116.11 Prepare methane
gas, (Experiment) See diagram 3.32: Collect insoluble gases over
1. Mix 1 part sodium acetate with 3 parts soda lime.
Heat in a dry pyrex test tube or flask.
Collect the gas over water.
2. Heat 20 g of sodium acetate-3-water in a Pyrex test-tube until the
salt becomes anhydrous.
Grind the cooled salt with an equal amount of soda lime [NaOH + Ca(OH)2]
granules in a mortar and pestle.
Mix thoroughly and place the mixture in a Pyrex test-tube.
Heat the test-tube and collect the gas over water. Be careful! Pull out the delivery tube before heating the water stops
so that water will not be "sucked back" into the
hot test-tube! For safety, wrap the test-tube in wire gauze.
CH3COONa + NaOH --> CH4 + Na2CO3
sodium acetate + sodium hydroxide --> methane + sodium carbonate 18.104.22.168 Tests for methane
gas, burn methane, (Experiment)
Light the gas in the test-tube with a glowing splint.
The gas burns with a clear flame.
CH4 + 2O2 --> CO2 + 2H2O
Repeat the experiment using glacial acetic acid soaked in glass wool
+ soda lime. 22.214.171.124 Methane with chlorine,
When a mixture of an alkane and chlorine gas are stored at low temperature
in the dark no reaction occurs.
At high temperatures or in sunlight, a substitution exothermic reaction
called chlorination occurs to produce chloromethane, methyl
chloride and HCl.
CH4 + Cl2 --> CH3Cl + HCl
Excess chlorine can produce dichloromethane (methylene chloride) trichloromethane
(chloroform) and tetrachloromethane (carbon
A mixture of chlorine and methane explodes violently in direct sunlight
forming hydrogen chloride and free carbon.
BE CAREFUL! Do not mix chlorine and methane!
CH4 (g) + 2Cl2 (g) --> C (s) + 4HCl (g) + energy 126.96.36.199 Reduce copper oxide
with natural gas, methane, (Experiment)
1. Pass natural gas, about 95% methane, over heated copper (II) oxide
The reduction reaction is slow and may need twenty minutes of strong
The copper does not glow with heating so it is not clear when all the
copper oxide has been reduced.
4CuO (s) + CH4 (g) --> 4Cu (s) + 2H2O (l) +
2. Repeat the experiment with a 1 cm cubic piece of metaldehyde in the
The reduction is quicker.
3. Repeat the experiment with natural gas that has bubbled through ethanol.
The reduction is quicker and a slight glow is seen as the copper oxide
6CuO (s) + C2H5OH (l) --> 6Cu (s) + 3H2O
(l) + 2CO2 (g) 188.8.131.52 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, now not allowed in schools, was used to soak up the
methyl iodide in the test-tube.)
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 184.108.40.206 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 220.127.116.11 LPG (Liquefied
Petroleum Gas, LP gas)
LPG is a clean burning fuel and is stored in gas cylinders as bottled
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.
Use a soap solution. 18.104.22.168 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
lighter gas. (in cigarette lighters and portable gas appliances), Highly
gas at room temperature, vapour pressure 2.4 atm.
Butane gas is stored as liquid under pressure in fire lighters and cannisters,
so 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, now not allowed in schools, was used to soak up the
ethyl iodide in the test-tube.)
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 22.214.171.124 Pentane (C5H12)
Pentane, b.p. 36.3oC, relative density 0.63, is made by distillation
of petroleum. 126.96.36.199 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. 188.8.131.52 Heptane (C7H16)
Heptane, b.p. 98oC, relative density 0.68, nine isomers, normal
heptane has similar properties to normal hexane. 184.108.40.206 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: 220.127.116.11: 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 the heat created in the cylinder by
Unleaded petrol has the octane rating 98.
Engine compression ratio
Octane number to be knock-free
Octadecan-1-ol, C18H38O, octadecyl alcohol, 1-octadecanol,
Use octadecan-1-ol for melting point curve experiments. 18.104.22.168, 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 22.214.171.124 Alkenes (CnH2n),
Alkene, R1R2C=CR3R4, (double
CC bond =), Prefix: alkenyl-, Suffix: -ene (no principal functional group)
Alkene, (olefins, olefines), CnH2n, e.g. ethylene,
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
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
2. The cycloalkenes, cycloolefins, are closed chain, non-aromatic forms,
e.g. cyclopropene, CH.CH.CH2, cyclobutene, cyclopentene,
cyclohexene. 126.96.36.199.1 Prepare ethene
(ethylene), C2H4 See 3.32.0: Prepare gases with a gas
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
apparatus. 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 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.
Cover the glass wool with porous pot and heat the porous pot.
C2H5OH --> C2H4 (g) +
H2O 3. Prepare ethene (ethylene) with ethanol, breakdown
of ethanol to ethene (ethylene, H2C=CH2). See 3.96: Breakdown ethanol to ethene
Ethene (ethylene, H2C=CH2), gas is a plant growth
It is produced in wounded, diseased and ripening tissues where it reacts
with auxins to induce fruit ripening and abscission of leaves or
It is used to ripen stored fruit artificially, e.g. bananas.
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
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
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. 4. Prepare ethene (ethylene), with ethanol, alternative
method See diagram 16.10.3: Prepare ethene
Absorb ethanol in cotton wool and push this to the bottom of a hard glass
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. 188.8.131.52.2 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.
3. Conjugated dienes have two double bonds separated by a single bond,
e.g. (buta-1,3-diene) (CH2=CH-CH=CH2) and
4. Unconjugated dienes, have two double bonds separated by two or more
5. Cyclodienes, 1.3-cyclohexadiene, 1.4-cyclohexadiene 184.108.40.206.3 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 | 220.127.116.11 Alkynes (CnH2n-2),
Alkyne, R1-CC-R2, (triple CC bond involves 6 electrons, e.g. acetylene,
Alkyne, Prefix: alkynl-, Suffix: -yne (no principal functional group),
1. acetylenes: ethyne (acetylene), (C2H2 (HCCH),
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),
Alkynes decolorize acidified potassium permanganate solution and bromine
2. The cycloalkynes, are closed chain, non-aromatic forms, e.g. cyclooctyne,
C8H12 (the smallest form). 18.104.22.168.0
Acetylene, C2H2, ethyne 22.214.171.124.1 Prepare
acetylene 126.96.36.199.2 Tests for
acetylene 188.8.131.52 Tests for gases from
burning hydrocarbons, oxyacetylene welding 184.108.40.206 Alcohols, phenols,
thiols, ethers, epoxy compounds, acetates (ethanoates) benzoyls, acetals See diagram 16.0.1: Tetrahedral geometry
of carbon, methane molecule, isobutyl alcohol
Alcohols (ROH), (-ol), alkanols, e.g. methanol (methyl alcohol), (CH3OH),
ethanol (ethyl alcohol), (C2H5OH)
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, secondary and tertiary
aliphatic alcohols, e.g. Primary alcohol, methanol, CH3OH,
Secondary alcohol, propan-2-ol, (CH3)2CHOH, Tertiary
alcohol, 2-methylpropan-2-ol, (CH3)3COH.
Alcohols, R-OH, are compounds in which a functional group, the hydroxyl
group, -OH, is attached to a saturated carbon atom,
The "hydroxyl" refers to the radical HO-.
The "alcohol" in alcoholic beverages is ethanol, ethyl alcohol, CH3CH2OH. 220.127.116.11a 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
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 clasified as "dangerous goods" 16.1.3.A Propanol (C3H7OH)
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.) 16.1.3.B 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),
(biobutanol), product of carbohydrate fermentation, common flavorant
2. Butan-2-ol, sec-butanol, 2-butanol, sec-butyl alcohol, (secondary
alcohol) CH3CH(OH)C2H5, (C4H9OH),
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,
(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 16.1.3.C Butyl glycol
2-butoxyethanol, butyl cellosolve, C4H9OCH2CH2OH,
butyl ether of ethylene glycol, pH 11. in window cleaner "Windex", inks,
solvents 18.104.22.168.1 Dihydric alcohols,
The dihydric alcohols, glycols, diols, have two hydroxyl groups on different
carbon atoms, e.g. 1. Ethane-1.2-diol,
ethanediol, glycol,1.2-dihydroxyethane, (HOCH2CH2OH),
(CH2OH.CH2OH), b.p. 197.5oC, car radiator
antifreeze, paint and
2. Butane-1.4-diol [HO(CH2]4OH]
CH2CH2 (oxidation) --> CH2OCH2
(+ water) --> HOCH2CH2OH
ethene (oxidation) --> epoxyethane (+ water) --> ethane-1.2-diol
(glycol, antifreeze) 22.214.171.124.2 Trihydric alcohols,
The trihydric alcohols, have three hydroxyl groups on different carbon
atoms, e.g. 1.2,3-trihydoxypropane, glycerol
[HOCH2CH(OH)CH2OH] 126.96.36.199.3 Nitroglycerine
(UK), Nitroglycerin (USA)
glycerol + cold mixture of concentrated sulfuric acid + nitric acid -->
ester of nitric acid
Nitroglycerine is a colourless, insoluble oil, solidifies on cooling,
contact explosive, used to make dynamite, cordite.
Nitroglycerine is a very unstable liquid that explodes if given a slight
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. 188.8.131.52.4 Nitrocellulose,
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. 184.108.40.206.1 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 220.127.116.11.1a 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
(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
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. 18.104.22.168.1a 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 coloration
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. 22.214.171.124.2 Prepare sodium
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. 126.96.36.199 Phenols
| See diagram 188.8.131.52: Phenols, quinones,
naphthols, coniferyl alcohol (p-coumaryl alcohol), urushiol, organohalogens
| See diagram 184.108.40.206: Phenols, quinones
| 220.127.116.11: Antioxidant phenols,
antioxidants, vitamin E, beta carotene
| 18.104.22.168.0: Cholesterol, C27H46O
1. Phenols, Ar-OH, are compounds with an hydroxyl group, -OH, firmly
attached to an aromatic ring, e.g. benzene, 2-naphthol,
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 22.214.171.124a Pyrogallol, C6H3(OH)3,
1.2,3-trihydroxybenzene, white crystals, reducing agent, alkaline solution,
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). 126.96.36.199.2 Naphthols See diagram 188.8.131.52: Phenols, Quinones,
naphthols | See 184.108.40.206: 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,
primary amines 220.127.116.11.3 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,
Toxic by all routes
(o-Cresol, ortho-cresol, 2-Methylphenol), colourless crystals
(m-Cresol, meta-cresol, 3-Methylphenol), liquid
(p-Cresol, para-cresol, 4-Methylphenol), solid 18.104.22.168.4 Resorcinol See diagram 22.214.171.124: 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,
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
Resorcinol, C6H6O2, argan oil, in Argania spinosa.
Prepare formaldehyde resorcinol resin: 126.96.36.199
Resorcinol, Xanthene dyes: 188.8.131.52 184.108.40.206.5 Triclosan,
organohalogens See diagram 220.127.116.11: 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. 18.104.22.168 Thiols (mercaptans) See diagram 22.214.171.124: Thiophenol (phenyl
mercaptan), | See diagram 16.13.10: Metam,
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),
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. 126.96.36.199.1 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 188.8.131.52.2 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 184.108.40.206.3 Ethyl mercaptan,
ethanethiol, CH3CH2SH, colourless gas, offensive
rotten cabbage smell, poisonous and used as
odorant 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. 220.127.116.11.4 Thiophene,
thiolane, THT, (CH2)4S
Thiophene, tetrahydrothiophene, colourless, unpleasant odour gas, used
as odorant in natural gas and LPG gas, (not in USA) 18.104.22.168 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) 22.214.171.124 Ethyl cellulose
Ethyl cellulose, cellulose ethyl ether, food additive emulsifier E462,
prepared from cellulose in wood and chemically ethylated,
thickening agent, filler, dietary fibre, anti clumping agent, emulsifier
Ethyl cellulose is no longer permitted as emulsifier in the EU, can be
fermented in the large intestine to cause bloating, constipation and
diarrhoea. 126.96.36.199 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) 188.8.131.52 Benzoyl group,
benzene carbonyl group C6H5CO-
e.g. benzoyl chloride (C6H5COCl) 184.108.40.206 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
POM) 220.127.116.11 Salts, e.g. sodium
ethanoate (sodium acetate) (CH3COONa), ammonium acetate (CH3COONH4)
NaHCO3 + CH3COOH --> CH3COONa + H2O
+ CO2 (g) 18.104.22.168 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. 22.214.171.124 Tests for unsaturated hydrocarbons,
bromine water tests for unsaturation 126.96.36.199 Tests for unsaturated hydrocarbons,
ignition tests for unsaturation 188.8.131.52 Acyl halide, acid
chloride, Acid chlorides group: (-COCL), Suffix: -oyl chloride
acyl chloride (RCOCl), e.g. ethanoyl chloride (acetyl chloride), (CH3COCl) 184.108.40.206 Amides, acid amides
(-amide), (amide group: -CONH2, RCONH2)
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
N.N-dimethylmethanamide HCON(CH3)2 (the polymer
group -CO-NH-), (inorganic amides, e.g. KNH2) 220.127.116.11a Carbamates See diagram 16.13.7: Carbamates, carbaryl,
Carbamates are derivatives of carbamic acid, NH2COOH.
Urethanes are esters of carbamic acid, i.e. alkyl carbamates.
Examples of cabamates: carbamic acid, ammonium carbamate, bendiocarb,
carbaryl, oxamyl, propoxur, urethane.
Combustion of carbamates may produce noxious NOx and carbon monoxide.
Carbametes 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. 18.104.22.168.1 Acrylamide,
C3H5NO, 2-propenamide, ethylene carboxamide, acrylic
amide, propenoic acid, UN 2074, vinyl amide
is toxic if ingested, crystalline form and aqueous solutions, monomer
Acrylamide, C3H5NO, CH2CHCONH2,
is the amide of acrylic acid, propenoic acid, (CH2CHCOOH), an
Acrylamide is a poison, harmful if swallowed, inhaled or absorbed through
skin, affects central and peripheral nervous systems and
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 expresso
rather than lungo, and avoiding overcooked foods. 22.214.171.124 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] 126.96.36.199 Imides (R1CO-NH-COR2),
(imido group: -CONHCO-), e.g. gluthemide (C13H15NO2).
The polymer group (-CO-NR-CO), polyimides, N-(trichloromethylthio), cyclohex-4-ene-1.
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,
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. 188.8.131.52 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). 184.108.40.206 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.) 220.127.116.11 Petrol, "gas",
gasoline, motor fuel
Mix of C6H14 to C11H24, 5
to 12 carbon atoms, alkanes and cycloalkanes, boiling range 40 to 205oC 18.104.22.168 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 22.214.171.124 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 126.96.36.199 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 188.8.131.52 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 184.108.40.206 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
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
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
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
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) 220.127.116.11 Reaction of acetone
with bleaching powder
CH3COCH3 + 3Cl2 --> CCl3COCH3
2CCl3COCH3 + Ca(OH)2 --> 2CHCl3
Ca(OH)2 + 2HCl --> CaCl2 + 2H2O 18.104.22.168 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
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 22.214.171.124 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
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
3Fe2O3 +11C --> 2Fe3C + 9CO (g) Types of carbides 1. Methanides, e.g. aluminium carbide, Al4C3
Hydrocarbyl anions, methyl anion, conjugate base of methane
Methanides + water --> methane, e.g. aluminium carbide, (Al4C3) 2. 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 +
calcium carbide + water --> acetylene + calcium hydroxide 3. Sesquicarbides,
C34-, e.g. Mg2C3 4. Covalent carbides,
e.g. boron carbide B4C, silicon carbide, SiC, (carborundum)
See: Models, inorganic,
carborundum, (silicon carbide), 30 "atoms", "Scientrific" (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 126.96.36.199: Amides 188.8.131.52 Nitriles
Nitriles (acid nitriles, alkyl cyanides, cyanides), (-CN, R-C triple
bond N), (note triple bond), Cyanide ion: CN- e.g. ethane nitrile,
(methyl cyanide, ascetonitrile) (CH3CN), 5-methoxyhexanenitrile,
acrylonitrile for making Orlon (vinyl cyanide, 1-cyanoethene), (CH2=CH-CN) 184.108.40.206.1 Cyanamides,
(inorganic, CN22-), ionization reaction of methylamine See diagram 220.127.116.11.1: 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
CaCn2 + H2O + CO2 --> H2NCN
calcium cyanamide + water + carbon dioxide --> cyanamide + calcium
(NH2)2CO --> HCNO + NH3
urea --> cyanic acid + ammonia
6HCNO --> C3H6N6 + 3CO2
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
formaldehyde and fish-like smell, thermosetting plastic, retains strength
and shape on heating
Melamine crockery, green, virtually unbreakable, dishwasher safe, Not
suitable for microwave oven, plate, 18 mm diameter 18.104.22.168.0 Amines, aliphatic
amines (RNH2-, R = alkyl group), ionization reaction
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,
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,
tetiary amine 22.214.171.124.01 Methylamine
CH3NH2 + H2O <--> CH3NH3+
+ OH- methylamine + water <--> methylammonium ion + hydroxide ion 126.96.36.199.02 Prepare phenylamine
1. Benzene + concentrated nitric acid + concentrated sulfuric acid -->
2. Nitrobenzene + tin catalyst Sn + reducing agent hydrochloric acid
--> phenylamine + water
C6H5NO2 + 6 H+ --> C6H5NH2
+ 2H2O 188.8.131.52.03 Nitrosamines
Nitrosamines are produced by reaction of nitrous acid with secondary
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
RDX explosive (Research Department Explosive, C3H6N6O6,
Cyclonite, Hexagen, used against German submarines during World
War II 184.108.40.206.04 Nitramine Nitramine, (acid-base indicator, 3.5),
C7H5N5O8, tetryl. colourless-yellow
crystals, explosive formerly used in munitions 220.127.116.11.05 Clenbuterol,
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. 18.104.22.168.1 Ethylenediamine
ClCH2CH2Cl + 4 NH3 --> H2NCH2CH2NH2
+ 2 NH4Cl
1.2-dichloroethane + ammonia --> ethylenediamine + ammonium chloride 22.214.171.124a 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) 126.96.36.199b Cyclic imines Pyrroline, C4H7N, 1-Pyrroline Acetyl pyrroline, C6H9NO,
2-acetyl-1-pyrroline, (2AP), substituted pyrroline, cyclic imine, ketone,
ethanone, white bread smell,
hot popcorn smell, jasmati and basmati rice smell, in Screwpine. 188.8.131.52 Nitroalkanes (nitroparaffins),
Nitromethane (CH3NO2), nitroethane, urea (carbamide) 184.108.40.206 Nitrites
(NO2-), dioxonitrate ion, salts or esters of nitrous acid,
Nitrites group: -C=N, Suffix: -nitrite, , e.g. sodium nitrite and potassium
as meat curing agents 220.127.116.11 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) 18.104.22.168 Cyanocrylates
e.g. "Superglue": Me or Et ester
Ethyl cyanoacrylate, "Superglue", BE CAREFUL! Do not squirt in the eye!
Toxic by all routes.
Commercial: 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). 22.214.171.124 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). 126.96.36.199 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 188.8.131.52 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
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 Phosphorous compounds,
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: Benomyl, captan, glyphosate,
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 184.108.40.206 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, (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 See diagram: Allyl isothiocyanate 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 isothiocyanate, (PEITC),
C9H9NS, in cruciferous vegetables, watercress, possibly
Phenyl isothiocyanate, (PITC), C6H5NCS,
Edman's reagent, isothiocyanatobenzene, colorless liquid, pungent odour,
used for amino
acids research sequencing peptides
C6H11NOS2, broccoli extract 220.127.116.11 Sulfides
Sulfides: RSR (R not equal to H), (old name: thioethers)
Diallyl disulfide C6H10S2, organosulfur
compound, from garlic and other Allium species, Alliaceae.
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
Diallyl disulfide has health benefits for most people, but some people
are allergic to it and most Allium species. Garlic
Oil of garlic contains diallyl disulfide, diallyl trisulfide and diallyl
Crushing garlic produces allicin, C6H10OS2.
Alliin is a a sulfoxide in fresh garlic produced from cysteine.
Allinase is an enzyme active in chopped or crushed garlic.
Alliin + allinase --> allicin , (allyl thiosulfinate), an unstable
antioxidant, which decomposes to diallyl disulfide (C6H10S2).
C6H11NO3S + allinase --> C6H10OS2.
Allicin causes the smell of fresh garlic. 18.104.22.168 Sulfonium compounds:
Sulfonium salts, e.g. trimethylsulfonium chloride [(CH3)3S]+Cl-,
Cyclopropyldiphenylsulfonium tetrafluoroborate, C15H15BF4S 22.214.171.124 Thiocyanates:
[RC(=O)SN] salts and esters of thiocyanic acid HSCN, e.g. methyl thiocyanate
(CH3SCN) 126.96.36.199 Siloxanes
Saturated silicon-oxygen hydrides with chains of alternating silicon
and oxygen atoms, e.g. unbranched [H3Si(OSiH2)nOSiH3],
"Volasil" is octamethylcyclotetrasiloxane.
Dimethylpolysiloxane is an anti-caking agent, emulsifier and anti-foaming
agent. 188.8.131.52 Sulfoxide, RS(=O)R',
contains a sulfinyl, SO, functional group
Alliin, L-Alliin, C6H11NO3S, ACSO, S-Allyl-L-cysteine
sulfoxide, SAC, aroma of Garlic 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
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
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
Ethanol, CH3CH2OH, C2H5OH,
absolute ethanol, denaturated with 4.8% methanol, ethyl alcohol, methylated
(95% CH3CH2OH, 5% CH3OH), 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.
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
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
Observe the rapid changes in colour during the dissolution of plant pigments
in methylated spirits.