A2 OCR Chemistry F324 definitions

A2 Chemistry F324 Definitions
A species that is a proton, H⁺, donor.
Addition Polymer
A very long molecular chain, formed by repeated addition reactions of many unsaturated alkene molecules (monomers).Only one product forms
An aromatic hydrocarbon.
Containing a ring with a delocalised π electron system.
A species that is a proton, H⁺, acceptor.
Processed fuel made from the transesterification of vegetable oil + methanol or ethanol. It can be used in unmodified diesel engines.
Chemical Shift
A scale that compares the frequency of an NMR absorption with the frequency of the reference peak of TMS at δ = 0 ppm.
Chiral Carbon (or Chiral Centre)
A carbon atom attached to four different groups.
A visible record showing the result of separation of the different components of a mixture by chromatography.
Condensation Polymer
A polymer formed by the joining up of monomers by means of a condensation reaction. A small molecule is eliminated, often water. Examples: proteins, polyamides, polyesters.
Condensation Reaction
A reaction in which two small molecules react together to form a larger molecule with the elimination of a small molecule such as water.
Delocalised Electrons
Electrons that are shared between more than two atoms.
E/Z Isomerism
A type of stereoisomerism in which different groups attached to each carbon of a C=C double bond may be arranged differently in space because of the absence of rotation around the C=C bond.
An atom (or group of atoms) that accepts a pair of electrons to form a new covalent bond.
Electrophilic Substitution
A type of substitution reaction in which an electrophile is attracted to an electron-dense centre or atom, where it accepts a pair of electrons to form a new covalent bond.
The reaction of an alcohol with a carboxylic acid to produce an ester and water.
Halogen Carrier
A compound such as AlBr₃ or FeBr₃ that can catalyse the halogenation of arenes. They produce a stronger electrophile, such as Br⁺.
A reaction where water is split that allows the breakdown of an organic molecule into two products. .Usually carried out under acidic or basic conditions, with slightly different products.
Isoelectric point
The pH at which an amino acid exists as its zwitterion.
Mobile Phase
The phase (gas or liquid) that moves in chromatography.
A small molecule that combines with many other monomers to form a polymer.
An atom (or group of atoms) which donates a pair of electrons to form a new covalent bond.
Optical Isomers
Stereoisomers that are non-superimposable mirror images of each other.
A compound containing amino acids linked by peptide bonds. Often the number of amino acids is indicated by the prefix, di-, tri-, tetra-.
Pharmacological Activity
The beneficial or adverse effects of a drug on living matter.
An arene that contains a hydroxyl (-OH) group directly bonded to one of the carbons in the aromatic ring. Phenol is both a compound (C₆H₅OH) and a functional group. Most phenols have antibacterial activity.
Pi (π) Bond
The part of a double bond formed above and below the plane of the bonded atoms by sideways overlapping p-orbitals.
A long molecular chain built up from monomer units.
A polypeptide (aminoacid polymer) with more than 40 or so monomers.
The continuous boiling and condensing of a reaction mixture to ensure that the reaction takes place without the contents of the flask boiling away.
Repeat Unit
A specific arrangement of atoms that occurs in the structure of a polymer over and over again. Repeat units are included in brackets, outside which is the symbol n.
Retention Time
The time for a component to pass through a chromatographic column up to the detector.
Stationary Phase
The phase that does not move in chromatography (normally a solid or a liquid adsorbed onto a solid).
Compounds with the same structural formula but with a different arrangement of the atoms in space.
Structural Isomers
Molecules with the same molecular formula but with different structural formulae.
Reaction in which an alcohol reacts with an ester to form another ester, effectively transferring the carboxylic acid group from one alcohol to another. Used to make biodiesel.
An unsaturated triglyceride containing one or more trans double bonds.
A triple ester formed by three fatty acids (relatively long carboxylic acids) bonded to a glycerol molecule. Oils and fats are triglycerides.
An ionic form of an amino acid that contains both positively and negatively charged groups. As both charges are present there is no overall charge.
Aliphatic Hydrocarbon
A hydrocarbon that is straight or branched.
Alicyclic Hydrocarbon
A hydrocarbon arranged in a ring structure.