Off By Heart Definitions Spring Test Flashcards
Sigma bond
Overlap of orbitals directly between bonding atoms
Homolytic fission
Breaking of a covalent bond where each atom retains one of the shared pair of electrons
Radical
A species with an unpaired electron
Pi bond
The sideways overlap of adjacent p orbitals above and below the bonding carbon atoms, there is restricted rotation
Stereoisomerism
Compounds with the same structural formula but different arrangements in space
E/Z isomerism
Restricted rotation around the pi bond and 2 different groups attached to each carbon atom of the C-C double bond
Cis-trans isomerism
A case of E/Z isomerism where 2 of the substituent groups attached to the C atoms of the C-C double bond are a H
Electrophile
An electron pair acceptor (cation or delta positive whether induced or permanent)
Heterolytic fission
A covalent Bond breaks and one of the atoms retains the shared pair of electrons forming an anion and a cation
Addition polymerisation
C-c double bond breaks open enabling free bonds to link with another one, forming a chain
Conditions for hydrogenation
Nickel catalyst, 150C
Hydration conditions
Phosphoric acid (H3PO4) and 300C
Isotope
Atoms of the same element with different amounts of neutrons and different masses
Relative isotopic mass
The mass of an isotope relative to the mass of 1/12 an atom of Carbon-12
Relative atomic mass
The weighted mean mass of atoms of an element relative the the mass of 1/12 an atom of carbon-12
Hydrated crystal
Water molecules are part of the crystalline structure
Water of crystallisation
The water within the structure of a hydrated crystal
Orbital
A region around the nucleus that can hold up to 2 electrons with opposite spins
Ionic bonding
The electrostatic attraction between positive and negative ions
Covalent bonding
The strong electrostatic attraction between the shared pair of electrons and the nuclei of the bonded atoms
Electronegativity
The ability of an atom to attract the bonding electrons in a covalent bond
Hydrogen bonding
The intermolecular bonds between N, O, F and the H of -ON, -OH, or Hf
1st ionisation energy
The energy required to remove 1 electron from each atom of 1 mole of gaseous atoms to from 1 mole of gaseous 1+ ions
Metallic bonding
The strong electrostatic attraction between cations and delocalised electrons
Structural isomers
Compounds with the same molecular formula but different structural formulae
Distillation
evaporation followed by condensation, which allows the most volatile component to be separated.
Heating under reflux
a process of continuous evaporation and condensation, which prevents the volatile components from escaping
Average bond enthalpy
A measure of covalent bond strength
Disproportionation
Oxidation and reduction of the same element
Structural isomer
Compounds with the same molecular formula but different structural formulae
Nucleophile
An electron pair donor
Enthalpy change of reaction
The enthalpy change that accompanies a reaction in the molar quantities shown in a chemical equation under standard conditions with all reactants and products in their standard states
Enthalpy change of formation
The enthalpy change that takes place when one mole of
a compound is formed from its elements under standard
conditions with all reactants and products in their
standard state.
Enthalpy change of combustion
The enthalpy change that occurs when 1 mole of a substance reacts completely with oxygen under standard conditions with all reactants and products in their standard state
Enthalpy change of neutralisation
The enthalpy change that accompanies the neutralisation of an acid by a base to form 1 mole water under standard conditions with all reactants and products in their standard state
Average bond enthalpy
Breaking of 1 mol bonds in gaseous molecules
Homogeneous catalyst
Catalyst same state as reactants
Eg. Hydration of alkenes
Heterogeneous catalysts
Catalyst different state to reactants
Eg. Haber process
Aliphatic
Straight/ branched chain
Alkyl
CnH2n+1
Alicyclic
Non-aromatic ring
Aromatic
Containing a benzene ring
Electron shielding
Inner electrons repel outer electrons reducing the attraction between the nucleus and outer shell electrons
