Definitions AS2 Flashcards
Empirical Formula
A formula which shows the simplest whole number ratio of atoms of each element in a compound.
Molecular formula.
A formula which shows the actual number of atoms of each element in a molecule.
Molar gas volume.
The volume of one mole of gas under specified conditions of temperature and pressure e.g. 24dm3 at 20°C and one atmosphere pressure.
Percentage yield
Shows how much product was actually made compared with the amount of product that was expected.
Theoretical yield.
The maximum mass of product expected from the reaction, using reacting masses.
Actual yield.
The mass of the product that is actually obtained from the real chemical reaction.
Homologous Series
Compounds with the same general formula
Similar chemical properties
Shows a gradation in physical properties
Successive members differ by CH2 unit
Functional group
Reactive group within a compound
Structural Isomers
Molecules which have the same molecular formula but different structural formula.
Geometric isomers/stereoisomers
Molecules with the same structural formula, but different arrangement of atoms due to the presence of one or more carbon double bonds.
Saturated hydrocarbon
Contains no double carbon bonds.
Contains hydrogen and carbon only.
Substitution
Replacing one atom or group with a different atom or group
Homolytic fission
Bond breaking in which one of the shared electrons goes to each atom.
Heterolytic fission
Bond breaking in which both electrons in a shared pair go to a single atom.
Radical
A particle with an unshared electron.
Sigma bond
A covalent bond formed by the linear overlap of atomic orbitals
Pi bond
A covalent bond formed by the sideways overlap of p orbitals
Bond length
The distance between the nuclei of two covalently bonded atoms.
Hydrogenation
Addition of a hydrogen molecule across a carbon double bond
Electrophile
An ion or molecule that attacks regions of high electron density.
Primary carbocation
A carbocation which has a carbon atom directly bonded to the positively charged carbon.
Secondary carbocation
A carbocation which has two carbon atoms directly bonded to the positively charged carbon.