Edexcel IGCSE Chemistry: Topic 4 - Organic Chemistry

Flashcard practice set focusing on IUPAC nomenclature, reaction types, crude oil refining, alkanes, alkenes, alcohols, carboxylic acids, esters, and addition/condensation polymers.

Hydrocarbon

A compound composed of hydrogen and carbon ONLY.

Empirical Formula

The simplest whole number ratio of each element present in a chemical compound.

Molecular Formula

The formula that shows the actual numbers of atoms of each element in a molecule of a compound.

General Formula

A type of empirical formula that represents the chemical composition of any member of an entire class of compounds (for example, $C_nH_{2n}$ for alkenes).

Structural Formula

A formula that indicates the arrangement of atoms in the molecule of a compound without drawing full bonds (such as $CH_2CH_2$ for ethene).

Displayed Formula

A graphical representation that shows the chemical symbols for each atom in a compound, using straight lines to represent covalent bonds.

Homologous Series

A series of compounds that share the same general formula and exhibit similar chemical properties.

Functional Group

A specific group of atoms that is directly responsible for the characteristic chemical reactions of an organic compound.

Isomerism

A phenomenon in which compounds that possess the same molecular formula exist in different structural forms due to distinct arrangements of atoms.

Addition Reaction

An organic reaction involving two reactants that join together to generate only one single product.

Substitution Reaction

An organic reaction involving two reactants that yields two products, wherein an atom or functional group in a molecule is replaced by another.

Complete Combustion

The reaction of a hydrocarbon fuel with excess oxygen producing exclusively carbon dioxide ($CO_2$) and water ($H_2O$).

Crude Oil

A finite, complex mixture of hydrocarbons consisting of molecules in which carbon atoms are arranged in chains or rings, serving as an essential source of fuels and petrochemical feedstock.

Fractional Distillation (Crude Oil)

The industrial continuous process of separating heated crude oil into fractions of similar carbon chain lengths based on differences in boiling point as vapours rise and condense up a fractionating column.

Refinery Gases

The fraction obtained from crude oil used primarily for domestic heating and cooking.

Gasoline / Petrol

The crude oil fraction utilised primarily as fuel for motor cars.

Kerosene

The fraction obtained from crude oil that serves as fuel for aircraft.

Diesel

The petroleum fraction used as fuel for certain cars and trains.

Fuel Oil

A crude oil fraction used as fuel for large marine ships and in some power stations.

Bitumen

A thick, dark, long-chain hydrocarbon fraction tapped from the bottom of the fractionating column, used to surface roads and roofs.

Fuel

A substance that releases heat energy when burned.

Incomplete Combustion

Combustion that occurs when the oxygen supply is limited, generating solid particles of soot (carbon), unburnt fuel, and poisonous carbon monoxide ($CO$).

Carbon Monoxide Poisoning

A life-threatening toxic condition occurring when inhaled carbon monoxide blocks the capacity of red blood cells to transport oxygen throughout the body.

Oxides of Nitrogen

Pollutant gases ($NO$, $NO_2$) created in car engines when extreme temperatures cause atmospheric nitrogen and oxygen to react together.

Acid Rain

Precipitation containing $H^+$ ions formed when sulfur dioxide and nitrogen oxides react with rainwater, which alters the pH of soils and rivers and corrodes limestone buildings and statues.

Catalytic Cracking

The thermal decomposition of long-chain alkanes into more valuable alkenes and shorter-chain alkanes over a silica or alumina catalyst at a temperature of $600\text{--}700^\text{o}\text{C}$.

Alkanes

A homologous series of saturated hydrocarbons characterised by the general formula $C_nH_{2n+2}$.

Saturated Hydrocarbon

A hydrocarbon containing no $C=C$ double bonds, in which each carbon atom has formed its maximum capacity of 4 single bonds.

Alkane Mono-substitution

A photochemical reaction where an alkane reacts with a halogen in the presence of ultraviolet (UV) radiation to produce a halogenoalkane and a hydrogen halide (e.g. $Br_2 + C_2H_6 \rightarrow C_2H_5Br + HBr$).

Alkenes

A homologous series of unsaturated hydrocarbons containing a carbon-carbon double bond functional group ($>C=C<$) with the general formula $C_nH_{2n}$.

Unsaturated Hydrocarbon

A hydrocarbon containing one or more carbon-carbon double bonds ($C=C$).

Bromine Water Test

A chemical test used to distinguish alkenes from alkanes; alkenes decolourise orange bromine water to colourless via an addition reaction, whereas alkanes do not react and it stays orange.

Alcohols

A homologous series of organic molecules that contain the hydroxyl functional group, $-OH$.

Microbial Oxidation

The process by which ethanol exposed to air reacts with atmospheric oxygen in the presence of microorganisms to produce ethanoic acid.

Hydration of Ethene

The industrial manufacture of ethanol by reacting ethene with steam over a phosphoric acid catalyst at about $300^\text{o}\text{C}$ and a pressure of $60\text{--}70\text{ atm}$.

Fermentation

The anaerobic conversion of glucose into ethanol and carbon dioxide using yeast enzymes at an optimum temperature range of $25\text{--}50^\text{o}\text{C}$ (about $30^\text{o}\text{C}$).

Carboxylic Acids

A homologous series of organic acidic compounds characterised by the functional group $-COOH$.

Vinegar

An aqueous solution containing ethanoic acid ($CH_3COOH$).

Esters

Volatile, pleasantly smelling organic compounds containing the functional group $-COO-$, widely used in perfumes and artificial food flavourings.

Ethyl Ethanoate

An ester with the structural formula $CH_3COOCH_2CH_3$, formed when ethanol and ethanoic acid react in the presence of an acid catalyst, producing water as a by-product.

Addition Polymer

A long-chain macromolecule formed when many small unsaturated monomer molecules join together without the formation of any other chemical by-product.

Condensation Polymerisation

A polymerisation process where a dicarboxylic acid reacts with a diol to form a polyester, releasing a small molecule (water) each time a new link is formed.

Biopolyesters

A specific class of synthetic polyesters engineered to be biodegradable by microorganisms, easing landfill and environmental disposal burdens.