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ORGANIC COMPOUNDS

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acetaldehyde

Another way of saying ethanal.

 

 

acetic acid

The old-fashioned name for ethanoic acid, which is found in vinegar.

CH3COOH

Also: C2H4O2

acetylene

Another way of saying ethyne.

 

 

acid chloride

Another way of saying acyl chloride.

 

 

acyl chloride

A compound containing the group RCOCl.  The acyl chloride group is similar to the carboxylic acid group, except that the hydroxyl group has been replaced with a chloride group.  Acyl chlorides are highly reactive.

RCOCl

alkanes (homologous series)

Hydrocarbons containing only carbon-carbon single bonds and carbon-hydrogen bonds

 

CnH2n+2

alkenes

(homologous series)

Hydrocarbons containing one or more carbon-carbon double bonds

 

CnH2n

alkynes (homologous series)

Hydrocarbons containing one or more carbon-carbon triple bonds

 

CnH2n-2

amyl nitrate

A colourless liquid added to diesel to improve ignition.

C5H11ONO2

amyl nitrite

A yellowish volatile synthetic liquid used medicinally as a vasodilator (a drug that makes blood vessels dilate) and inhaled as a recreational drug.

 

Sometimes it is called amyl nitrate, but this misleading.  Amyl nitrate is used in diesel.

C5H11ONO

benzene

A volatile liquid hydrocarbon present in coal tar and petroleum, having a hexagonal ring-shaped molecule which is the basis of most aromatic organic compounds.

 

The simplest aromatic compound, a member of the arene homologous series, a known carcinogen (cancer causing chemical) and a constituent of petrol in the UK.  It has a system of delocalised electrons that occur because of overlap between the π-orbitals (the pear-shaped orbits of the electrons in the second of the two bonds making up the three double bonds in benzene).

 

Origin of name: benzoic acid + ene (denoting double bonds).  Benzoic acid is a white crystalline compound present in the plant resin benzoin. 

 

Benzoin is a fragrant gum resin obtained from certain East Asian storax trees.  A crystalline aromatic ketone present in this resin is also called benzoin, from which benzoic acid takes its name. 

 

Benzoin the resin is named from the French benjoin from the Arabic lubānjāwī meaning incense of Java.

    

C6H6

chloroform

AKA tetrachloromethane or carbon tetrachloride, this anaesthetic liquid can be fatal in overdose.

       

CCl4

dioxin

Carcinogenic polluting compound, full name 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

C12H4Cl4O2

ester

A molecule made from an alcohol and a carboxylic acid.  The link between the alkyl groups of the two constituent molecules is called an ester link.

RCOOR

ethanal

The aldehyde that is based on ethane.  It has two carbon atoms, one with three hydrogen atoms attached, and the other doubly bonded to an oxygen atom and singly bonded to a hydrogen atom.

Also called acetaldehyde.

CH3CHO

 

ethanoic acid

A carboxylic acid formed by the oxidation of ethanol.

CH3COOH

Also: C2H4O2

ethanol

The alcohol based on ethane.  Click here for loads more detail.

CH3CH2OH

 

Also: C2H5OH or C2H6O

ethene

A colourless, highly flammable gas.

C2H4

ether

Ethoxyethane, used as an anaesthetic.

CH3OCH3

ethers

(homologous series)

Organic chemicals whose molecules consist of two alkyl groups bonded to either side of an oxygen atom.

ROR’

ethyl

An alkyl group consisting of –CH2-CH3 (–C2H5).  It’s basically just ethane with one hydrogen atom removed.

C2H5-

ethyl alcohol

An old-fashioned name for ethanol.

 

 

ethylene

An old-fashioned name for ethene

 

 

ethylene glycol

Systematically called ethanediol, a colourless viscous hygroscopic liquid used in antifreeze and in wood preservatives.

C2H6O2

ethyne

The first member of the alkyne homologous series, formerly known as acetylene.

C2H2

formic acid

The old-fashioned name for methanoic acid.

 

 

furan

One half of the 80s chemical pop sensation Furan Furan.

C4H4O

glycerol

Systematic name called propane-1,2,3-triol.  The molecule at the heart of fats and oils, this trihydric alcohol is also used to make bubble mixture and in the catering industry.  It is sometimes referred to as glycerine.

C3H5(OH)3

hexane 1,6-diamine

Mixed with hexanedioic acid to make nylon(6,6).

Also called 1,6-diaminohexane.

C6H16N2

hexanedioic acid

Mixed with hexane 1,6-diamine to make nylon(6,6).

C6H14O4

hydrocarbons

Compounds containing only hydrogen and carbon atoms.

 

CXHY

methanoic acid

The simplest carboxylic acid possible.

HCOOH

Also: CH2O2

Methylene Blue

An indicator with many other uses including staining cells in biology and related sciences, and as a medicinal drug.

C16H18ClN3S

PET

PolyEthylene Terephthalate, a polymer used to make drinks bottles, x-ray films, audio tapes and many other products.  As an artificial fibre it is known as Terylene® and Dacron®.

(C10H8O4)n

pyran

 

C5H10O

sebacoyl chloride

A diacyl dichloride also known as decanedioyl dichloride.  It is used in Salters Advanced Chemistry Activity DP2.1 Making Nylon (click to view details of this activity).

C10H16Cl2O2

tetrahydrofuran

A clear colourless liquid which smells like ether and dissolves easily in organic solvents and water.

C4H8O

 

 

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INORGANIC COMPOUNDS

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copper(I) oxide

A brick red powdery solid, formed when copper(II) ions (Cu2+) are reduced in alkaline aqueous solutions to copper(I) ions (Cu+).

Crystal lattice structure

Cu2O

copper(II) oxide

The more common oxide of copper.

Crystal lattice structure

CuO

gunpowder

An explosive consisting of a powdered mixture of saltpetre, sulphur and charcoal.

Mixture

KNO3, S, C

gypsum

A soft white or grey mineral consisting of hydrated calcium sulphate, used to make plaster of Paris and in the building industry.

 

CaSO4.2H2O

hydrofluoric acid

A powerful acid used to etch glass, this liquid is extremely dangerous.

 

As an anhydrous compound, hydrogen fluoride is a viscous, fuming liquid.  Unlike hydrogen chloride it is not a gas at room temperature due to the very strong hydrogen bonding between neighbouring molecules. 

 

This arises because of fluorine’s uniquely high electronegativity.  The structure to the right shows that the fluorine atom strongly attracts electrons in the hydrogen-fluorine covalent bond, resulting in a massive dipole effect.

 

Although technically a weak acid, HF is highly dangerous as it destroys biological tissues at a frightening rate, penetrating deep into human flesh.  If you spill HF on your hand, it may have etched away down to the bone before you realise anything is wrong.  Calcium gluconate gel can be used in treatment.

+δHFδ-

HF

hydronium ion

Another word for the hydroxonium ion.

 

 

hydroxonium ion

The ion formed when protons dissociate from their parent acid molecule in aqueous acid solutions.  Click here for more details.

 

H3O+

oxonium ion

Another word for the hydroxonium ion.

 

 

phosphate ion

The anion found in phosphoric acid.  It also makes up part of the backbone of DNA and RNA, interspersed by ribose sugar units.

 

PO43-

potassium cyanide

A highly poisonous solution containing cyanide (CN-) ions.

 

 

KCN

Extremely toxic

sodium tetrahydridoborate(III)

Powerful reducing agent used in organic synthesis.

 

NaBH4 is a source of hydride ions (H-) which act as reducing agents by adding hydrogen to organic compounds.

 

As a quick recap of OIL RIG, oxidation is:

·          loss of electrons

·          gain of oxygen

·          loss of hydrogen

 

Reduction is:

·          gain of electrons

·          loss of oxygen

·          gain of hydrogen

 

It is less reactive than the more powerful reducing agent lithium tetrahydridoaluminate(III) (also known as lithium aluminium hydride) which means it is safer to use.

 

The +3 oxidation state of boron indicated in the name is a bit of a pointless piece of information to include because boron has a +3 oxidation state in all its compounds.

 

Synonym: sodium borohydride.

NaBH4

sulphate ion

[sulphate(VI)]

Although this diagram shows double bonds and two single bonds, in real life each sulphur-oxygen bond is identical.  Four of the electrons in the double bonds in the picture are actually spread out equally between all the atoms.  They are delocalised over the whole ion, just like the double bonds in benzene.

 

SO42-

superoxide ion

The anion O2-

 

O2-

tungstate

A salt in which the anion contains both tungsten and oxygen.  Tungstate (VI) has the formula WO42-.

WO42-

tungsten

The chemical element of atomic number 74, a hard steel-grey metal with a very high melting point (3410°C), used to make electric light filaments.

Metallic lattice structure

W

tungsten carbide

A very hard grey compound made by reaction of tungsten and carbon at high temperatures, used in making engineering dies, cutting and drilling tools, etc.

Crystal lattice structure

WC

tungstite

A yellow mineral consisting of hydrated tungsten oxide, typically occurring as a powdery coating on tungsten ores.

Crystal lattice structure

WO3.H2O

water

A highly polar molecule, liquid at room temperature, formed when hydrogen gas (H2) burns in air or in pure oxygen.

 

Liquid water exists almost entirely as covalent water molecules.  Its pH is 7, which corresponds to a concentration of H+(aq) ions of only 10-7 mol dm-3.

 

In comparison, a strong acid such as hydrochloric acid has a pH of about 1, which corresponds to a [H+(aq)] of 10 mol dm-3, which is one hundred million times more than water.

H2O

 

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FOODS, MEDICINES, DRUGS & POISONS

 

aspirin

A synthetic drug developed in the 1890s used to relieve pain and reduce fever.  It is derived from salicylic acid, which itself comes from salicin, a compound found in willow trees.

 

Origin of name: aspirin was discovered by Felix Hoffman, a German chemist.  The German name for the compound is acetylierte Spirsäure (acetylated salicylic acid).  This became shortened to aspirin.

C9H8O4

Mr = 180

Synonyms:

2-ethanoylhydroxybenzoic acid

acetylsalicylic acid

caffeine

A drug found in tea, coffee, chocolate and Coke. 

 

Caffeine gives people a lift and helps them to be mentally alert.  The drug is used medically to stimulate the nervous, respiratory and cardiovascular systems. 

 

Caffeine is also added to medicines to counteract sleepiness caused by other ingredients.

C8H12N4O2

Mr = 182

Synonyms:

1,3,5-trimethylxylene

heparin

A compound occurring in the liver and other tissues which inhibits blood coagulation, used as an anticoagulant in the treatment of thrombosis.

 

Origin of name: from Greek hepār (liver) + in (an ending used for organic compounds, pharmaceutical products, proteins and so on)

 

Mr = 6000 to 40000

 

ibuprofen

An anti-inflammatory and analgesic drug sold over the counter.

 

Origin of name: certain parts of the name 2-(4-isobutylphenyl) propionic acid.

C13H18O2

Mr = 206

Synonyms:

2-(4-(2-methylpropyl)phenyl propanoic acid

2-(4-isobutylphenyl) propionic acid

paracetamol

A synthetic drug used to relieve pain and reduce fever and swelling.  Paracetamol is regularly used in hospitals and is sold over the counter by pharmacists.

 

Origin of name: one name for the structure of the compound is paraacetylaminophenol.  In the 1950s this became shortened to paracetamol.

C8H9NO2

Mr = 151

Synonyms:

acetaminophen (USA)

maltose

A sugar produced by the breakdown of starch, sometimes by enzymes found in malt.

C12H22O11

mannose

A sugar which occurs as a component of many natural polysaccharides and is part of the hexose class of sugars.

C6H12O6

morphine

Powerful painkiller related to heroin.  Me stands for –CH3.

morphine

 

 

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DICTIONARY

 

acid hydrolysis

Hydrolysis that is carried out in an acidic solution.

absolute zero

Zero Kelvin (0 K) or -273.15 °C which is the lowest temperature theoretically possible.  At this temperature atoms do not vibrate at all, resulting in no heat.  It is impossible to achieve absolute zero in real life, but it is possible to get very close (a few millionths of a degree above).

absorbance

A measure of the capacity of a substance to absorb light of a specified wavelength, often used in colorimetry. 

It is given in terms of I0 (intensity of light at source) and I (intensity of light after passing through substance) by this equation: A = -log10(I/I0)

 It is also given by Beer’s Law A = εℓc where ε is molar absorptivity, is path length of light and c is concentration.

If Greek letters such as ε confuse or annoy you, try looking at my sheet about the Greek alphabet.

aromatic

(When relating to an organic compound) containing a planar unsaturated ring of atoms which is stabilised by an interaction of the bonds forming the ring.

degradation

The reverse process of synthesis, where a large molecule is broken down into smaller, simpler molecules.

degradation

A process where a large molecule is broken down into simpler ones.

deliquesce

To become liquid by absorbing moisture from the air (talking about a solid).

electron

A lepton with a charge of -1 relative to the charge on a proton.  The charge on an electron is 1.6 x 10-19 Coulombs.

erythrocyte

a red blood cell

esterase

an enzyme which breaks down particular esters into acids and alcohols or phenols

hydro-

Water or water-related (like in hydrolysis) or it can mean hydrogen (like in hydrochloric acid or hydrocarbon).  Hydro- came directly from the Greek word for water hudron.

hydrolysis

A reaction where a molecule is split by water.

hygroscopic

A substance that tends to absorb moisture from the air is hydroscopic.

lachrymator

An eye irritant.

-lysis

Decomposition.  I like to think of it as meaning splitting.  It came from the ancient Greek word lusis which means loosening.  It’s easy to see how loosening is similar to decomposition – when something loosens it is held less strongly.  When the knots in a net loosen the net decomposes, it falls apart.

 

Electrolysis means chemical decomposition by electric current.  The electrons holding a compound together are loosened and let free by adding more electrons from an electric current.  As a result the compound decomposes.

 

Catalysis means using a catalyst to accelerate a chemical reaction.  The word came from kataluein, a Greek verb meaning dissolve, which in turn is made up of kata (down) and luein (loosen).  This is an example of a word where it’s harder to see the connection between its constituent parts and its meaning.

 

Hydro- means water and glyco- means glucose.

Hydrolysis means chemical breakdown due to reaction with water and glycolysis means the breakdown of glucose by enzymes.  The part of the word before –lysis can refer to either the thing causing the splitting (water) or the thing being split (glucose).

methyl-

Containing the alkyl radical –CH3 which comes from methane.

para-

Complicated: denoting substitution at diametrically opposite carbon atoms in a benzene ring, for example paradichlorobenzene

 

Simple: when you have two groups attached to a benzene ring, there are three different isomers possible.  The para- isomer is the one where the two groups are opposite each other, and are as far away from each other as possible.  The other isomers are called ortho- (next-door neighbours) and meta- (separated by one notch).

 

Important note: para-, meta- and ortho- are not standard IUPAC-approved ways of describing the structure of chemicals.  They are getting a bit outdated and most newly-published books will use the systematic IUPAC nomenclature (naming system).  Even though IUPAC is trying to get everyone to speak their new language, many older documents and some new ones still use the old fashioned names.  For one thing, the names look ridiculous using the systematic nomenclature: paradichlorobenzene becomes 1,4-dichlorobenzene.  Who wants to be faffing around with all those numbers?  Apparently they’re supposed to remove any ambiguity, but that’s debatable. 

 

 

Origin of the word: the prefix comes from the Greek word para (παρα), meaning beside or beyond.

 

Not to be confused with the Northampton slang para, a shortened form of paralytic, meaning extremely drunk.  Paralytic comes from paralysis – because it is possible drink so much that you can’t stand up, at which point you have achieved at least one symptom of paralysis.  Although many people will testify that this is true, getting para is not recommended. (Included for legal reasons only).

pharmaceutical

(Adjective) of or relating to medicinal drugs, or their preparation, use or sale

(Noun) a compound manufactured for use as a medicinal drug

 

Origin of the word: via late Latin from Greek pharmakeutikos [from pharmakeutēs (druggist) from pharmakon (drug)].

pharmacology

The branch of medicine concerned with the uses, effects and action of drugs.

pharmacy

  1. A place where medicinal drugs are prepared (e.g. in a hospital) or sold (e.g. in a shop)
  2. The science or practice of preparing and dispensing medicinal drugs

 

Origin of the word: via medieval Latin and Old French farmacie from Greek pharmakeia (φαρμακεια) meaning practice of the druggist, based on pharmakon (φαρμακον) meaning drug.

supercool

To cool a liquid below its freezing point without solidification or crystallization.

synthesis

The process of making a new substance from simpler substances.  Compare with degradation.

thermochemistry

The branch of chemistry concerned with the quantities of heat evolved or absorbed during chemical reactions.

thermolabile

Readily destroyed or deactivated by heat.  Compare with thermostable.

thermolysis

The breakdown of molecules by the action of heat.

thermostable

Not readily destroyed or deactivated by heat.  Compare with thermolabile.

viscous

Sticky or thick, like treacle.

 

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