CCEA 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.
Molecular Gas Volume
The volume of one mole of gas under specified conditions of temperature and pressure.
Percentage Yield
% yield= actual yield of product/theoretical yield of product x 100
Atom economy
% atom economy = mass of desired products/total mass of products x100
Homologous series
Compounds which have the same general formula, similar chemical properties, show a gradation in physical properties and successive members differ by a CH2 unit.
Functional group
Reactive group within a compound.
Structural isomers
Molecules which have the same molecular formula but a different structural formula.
Geometric isomers
Molecules which have the same structural formula, but different arrangements of atoms due to the presence of one or more C=C bond.
Saturated hydrocarbon
Contains only single bonds.
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 C=C.
Electrophile
An ion or molecule that attacks regions of high electron density.
Primary carbocation
A carbocation which has one 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.
Tertiary carbocation
A carbocation which has three carbon atoms directly bonded to the positively charged carbon.
Polymerisation
Joining together of many small molecules (monomers) to form a large molecule.
Monomers
Many small molecules which join together to form a polymer.
Primary halogenoalkane
A halogenoalkane which has one carbon atom directly bonded to the carbon atom that is bonded to the halogen. (Exceptions are halomethanes).
Secondary halogenoalkane
a halogenoalkane which has two carbon atoms directly bonded to the carbon atom that is bonded to the halogen.
Tertiary halogenoalkane
A halogenoalkane which has three carbon atoms directly bonded to the carbon atom that is bonded to the halogen.
Reflux
Repeated boiling and condensing of a (reaction) mixture