Unit 2: Chains, Energy and Resources

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General Formula
The formula that represents all the straight and branched chain compound in a class of compounds.
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Empirical Formula
The simplest whole number ratio of atoms of each element present in a compound.
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Molecular Formula
The actual number of atoms of each element present in a molecule.
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Structural Formula
The minimum amount of detail required to show the unambiguous arrangement of atoms in a molecule.
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Displayed Formula (Full Structural Formula)
The structural formula showing every atom and every covalent bond.
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Skeletal Formula
The structural formula showing only the bonds between carbon atom and the functional groups.
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Hydrocarbon
A compound that contains only carbon and hydrogen atoms.
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Saturated
A compound containing only single covalent bonds.
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Unsaturated
A compound containing one or more carbon-carbon double bonds.
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Homologous series
A series of organic compounds having the same functional group but with each successive member differing by CH2.
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Functional Group
A group of atoms responsible for the characteristic reactions of a compound.
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Structural Isomers
Compounds with the same molecular formula but different structural formula.
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Stereoisomers
Compounds with the same structural formula but with a different spatial arrangement of their atoms and bonds.
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E/Z Isomerism
An example of stereoisomerism that arises due to restricted rotation about a carbon-carbon double bond. There must be two different groups attached to each carbon atom of the carbon-carbon double bond.
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Cis-Trans Isomerism
A special type of E/Z isomerism in which two of the substituent groups are the same.
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Homolytic fission
The symmetrical breaking of a covalent bond, with one of the bonding electrons going to each atom, forming two radicals.
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Heterolytic fission
The unsymmetrical breaking of a covalent bond, with both of the bonding electrons going to only one of the atoms, forming a cation (+) and an anion (-).
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Radical
A species with an unpaired electron.
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Nucleophile
A lone pair of electrons donor with the formation of a dative covalent bond.
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Electrophile
A lone pair of electrons acceptor with the formation of a covalent bond.
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Substitution
A reaction in which an atom or functional group is replaced by another atom or functional group.
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Addition
A reaction in which two or more reactants combine to make a single product.
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Condensation
A reaction in which two organic molecules join together with the elimination of a small molecule from the linkage.
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Esterification
A special type of condensation reaction in which an ester is formed from a carboxylic acid and an alcohol with the elimination of water from the linkage.
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Oxidation
Addition of oxygen or removal of hydrogen.
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Reduction
Addition of hydrogen or removal of oxygen.
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Hydration
Addition of water (or steam).
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Hydrolysis
Reaction with water or aqueous sodium/potassium hydroxide.
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Fermentation
The reaction in which ethanol is formed from glucose.
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Cracking
A reaction in which long chain alkane molecules are broken down into a mixture of smaller alkane and alkene molecules.
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Addition Polymerisation
A reaction in which long chain molecules are formed from smaller molecules which contain a carbon-carbon double bond.
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Reflux
Continuous heating without loss due to evaporation.
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π-bond
A covalent bond formed by the overlap of two p-orbitals resulting in a region of high electron density above and below the molecule.
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Biofuel
A fuel that can be obtained from plants or animals.
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Bioethanol
Ethanol that is made fermentation from plant with a high starch or sugar content.
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Biodiesel
A fuel made by transesterification from oil-rich algae or plants with oil-rich seeds.
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Biomass
Waste material from plants and animals.
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Atom Economy
(Molecular mass of desired products ÷ Sum of molecular masses of all products) x 100%
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Percentage Yield
(Actual moles of product ÷ Expected moles of product) x 100%
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Volatility
The ease with which a liquid turns into a gas (the ease with which a liquid boils; as volatility increases boiling point decreases).
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Fingerprint Region
The region of the infrared spectrum between 1500 and 400cm-1.
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Molecular Ion
The ion formed when a complete molecule of the sample loses only one electron.
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Molecular Ion Peak
The peak with the greatest mass/charge ratio, which gives a direct reading of relative molecular mass.
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Base Peak
The peak for the most abundant fragment ion (set at 100%).
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Exothermic
A reaction is which heat energy is released to the surroundings; ΔH is negative.
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Endothermic
A reaction in which heat energy is absorbed from the surroundings; ΔH is positive.
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Standard Conditions
Pressure= 100kPa, Temperature= 298K (25°C).
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Standard State
The normal physical state of a substance under standard conditions.
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Standard Enthalpy Change of Reaction, ΔH°r
The enthalpy change that accompanies a reaction in the molar quantities expressed in the chemical equation, at 100kPa and 298K, all reactants and products being in their standard states.
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Standard Enthalpy Change of Formation, ΔH°f
The enthalpy change that occurs when one mole of a compound is formed from its elements in their standard states at 100kPa and 298K.
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Standard Enthalpy Change of Combustion, ΔH°c
The enthalpy chnage that occurs when one mole of a substance reacts completely with oxygen at 100kPa and 298K, all reactants and products being in their standard states.
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Average (mean) Bond Enthalpy
The enthalpy change that occurs when one mole of a given type of covalent bond is broken, averaged across a range a compounds in the gaseous state.
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Hess's Law
The overall enthalpy change for a reaction is the same irrespective of the route taken, as long as the initial and final conditions are the same.
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Rate of Reaction
The change in concentration of a reactant or product in a given time. The gradient of a graph of concentration against time.
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Activation Energy
The minimum amount of energy required to start a reaction by the breaking of bonds.
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Catalyst
A substance that increases the rate of reaction without being consumed.
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Homogeneous Catalyst
A catalyst in the same physical state as the reagents and products.
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Heterogeneous Catalyst
A catalyst in a different physical state as the reagents and products.
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Le Chatelier's Principle
When a system in dynamic equilibrium is subjected to change, the position of equilibrium will shift to minimise the change.
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Dynamic Equilibrium
When both opposing reactions are proceeding at the same rate.
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Compromise Temperature
High enough to give a suitable rate of reaction but low enough to give a suitable yield when the forward reaction is exothermic.
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Compromise Pressure
High enough to give a suitable rate of reaction but low enough to give a suitable yield when the forward reaction gives more moles of gas.
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Compromise Pressure
High enough to give a suitable yield when the forward reaction gives fewer moles of gas, but not so high that the plant is dangerous and too expensive to maintain.
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Pollutant
A chemical substance in the wrong place where it has a harmful effect.
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Stratosphere
The upper atmosphere (where ozone is beneficial and not a pollutant).
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Troposphere
The atmosphere close to ground level (where ozone is a pollutant).
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Greenhouse Effect
The natural process by which sunlight is absorbed by plants and converted to heat energy which is absorbed by gases in the atmosphere and radiated back to earth.
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Global Warming
The enhanced greenhouse effect due to the increase in the concentration of gases in the atmosphere capable of absorbing heat energy, resulting in an increase in global temperature.
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Other cards in this set

Card 2

Front

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

Back

Empirical Formula

Card 3

Front

The actual number of atoms of each element present in a molecule.

Back

Preview of the back of card 3

Card 4

Front

The minimum amount of detail required to show the unambiguous arrangement of atoms in a molecule.

Back

Preview of the back of card 4

Card 5

Front

The structural formula showing every atom and every covalent bond.

Back

Preview of the back of card 5
View more cards

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