chemistry module 4 definitions Flashcards
aliphatic
a hydrocarbon where all carbon and hydrogens are contained in either branched chains, unbranched chains or non-aromatic rings
alicyclic
an aliphatic compound arraged in non-aromatic rings
alkyl
a group with the general formula CnH2n+1
dipole
a partial charge created by differences in electronegativity between two covalently bonded atoms
curly arrow
shows the movement of electrons & has to start from
-lone pair
-bond
-negative charge
empirical formula
the simplest whole number ratio of each element present in a compound
displayed formula
the relative positions of atoms and the bonds between them
general formula
the simplest algebraic formula for a member of a homologus series
homologus series
a series of organic compounds containing the same functional group with each member successive by ch2
heterolytic fission
when a covalent bond breaks, one bonding pair of electrons receives both electrons from the bonded pair
homolytic fission
when a covalent bond breaks, each bonding pair of electrons receives one electron from the bonded pair
nomenclature
the naming system for compounds
radical
species with an unpaired electron
reaction mechanism
a series of steps that represent the reaction by showing the breaking and forming of bonds using curly arrows
structural isomers
same molecular formula but different structural formula
structural formula
the minimal detail that shows the detail that shows the arrangement of atoms in a molecule
bond enthalpy
the energy required to break down 1 mol of gaseous atoms
london forces
induced dipole-dipole forces that caused by the random movement of electrons
polar bond
when a large disparity in electronegativity makes it so that the bonded pair of electrons are held closer to the more electronegative element. there is a permanent dipole
initiation
first step in free radical substitution mechanism where free radicals are created from UV
termination
last step in free radical substitution wherein 2 radicals react to create a species with only paired electrons
propagation
intermediate step in free radical sub in which the free radical reacts with another species
sigma bond
single bond, formed by the overlapping of the s-orbitals head-on and these can rotate freely
pi bond
a type of covalent bond formed where adjacent p orbitals overlap sideways above and below the bond
ing atoms
addition reaction
a reaction where molecules combine to form a single product
addition polymerisation
the formation of long chain molecules when many monomers join together
bond enthalpy
the energy required to break one mole of gaseous bonds. Actual bond
enthalpies may differ from the average as the average bond enthalpy considers a particular
bond in a range of molecules.
e isomer
when highest priority groups are on the opposite sides of the double bond (entengen)
z isomer
when the highest priority group is on the same end of the double bond
catalyst
speed up rate of reaction without being used up