organic chemistry keywords Flashcards
compounds made up of carbon and hydrogen only
hydrocarbons
the formula that tells us the simplest ratio of the different atoms present in a molecule
empirical formula
the formula that tells us the actual numbers of each type of atom in a molecule
molecular formula
the formula that tells us about the atoms bonded to each carbon atom in an organic molecule, e.g. CH3CH=CH2
structural formula
a drawing of a molecule that shows all the atoms and bonds within the molecule
displayed formula
a simplified version of the displayed formula, having all the symbols for C and H atoms removed as well as the C to H bonds, but still showing the C to C bonds left in place
skeletal formula
an atom or group of atoms in an organic molecule that determine the characteristic reactions of a homologous series
functional group
a formula that represents a homologous series of compounds using letters and numbers. e.g. the (it) for the alkanes is CnH2n+2. By substituting a number for n in the general formula you get the molecular formula of a particular compound in that homologous series
general formula
a shared pair of electrons bonding two atoms together
single covalent bond
single covalent bonds, formed by the ‘end-on’ overlap of atomic orbitals
sigma (σ) bonds
multiple covalent bonds involving sideways overlap of p atomic orbitals
pi (π) bonds
compounds with the same molecular formula but different structural formulae
structural isomers
when the position of the functional group varies in each isomer
position isomerism
when there are different functional groups present in each isomer
functional group isomerism
when the structure of carbon ‘skeleton’ differs in each isomer
chain isomerism
compounds with the same structural formula with atoms arranged differently in space
stereoisomers
geometric isomerism in unsaturated compounds or cyclic compounds depending usually on the presence in the molecule of a pair of substituted groups (as unsymmetrically substituted methylene groups) so that the stereoisomers have comparable substituents on either the same or opposite sides of the molecule. different phy and chem properties
cis-trans isomerism
Stereoisomers who are non-superimposable mirror images. The isomers display identical characteristics in terms of molecular weight as well as chemical and physical properties. However, they differ in their effect on the rotation of polarized light.
optical isomerism
a carbon atom with four different groups attached, creating the possibility of optical isomers. but actually optical isomers chiral centrenya bs atom apa aja, gk mesti C.
chiral centre
a type of bond breaking where both the atoms of each end of the bond leave with one electron from the pair that formed the covalent bond, producing free radicals
homolytic fission
species produced when a bond breaks homolytically. very reactive atom or molecule that has a single unpaired electron
free radical
the first step in the mechanism of free-radical substitution of alkanes by halogens. It involves the breaking of the halogen-halogen bond by UV light from the Sun
initiation step
reaction involving the formation of free radicals, requiring an input of energy to break a covalent bond, resulting in two free radicals
initiation step
a step in a free-radical mechanism in which the radicals formed can then attack reactant molecules generating more free-radicals, and so on, chain reaction.
propagation step