definitions Flashcards
Relative atomic mass
The weighted mean mass of an atom of an element compared with one-twelfth of the mass of an atom of carbon-12
Molecular or complex ions
Groups of covalently bonded atoms that can lose or gain electrons to form ions
Molar gas volume
The volume per mole of a gas (dm3mol-1)
Covalent bond
Strong electrostatic attraction between a shared pair of electrons
Dative covalent bond
A type of covalent bond in which both of the electrons in the shared pair come from one atom
Ionic bond
The electrostatic attraction between two oppositely charged ions
Metallic bond
Electrostatic attraction between metal cations and delocalised electrons
Homologous series
Family of compounds with the same functional group but each successive member differs by CH2
Atomic orbital
A region of space that can contain 2 electrons with opposite spins
Sub-shell
All the orbitals of the same type within one shell
Standard solution
A solution of known concentration
Structural isomers
Compounds with the same molecular formula, but different structural formula
Stereoisomers
Compounds with the same structural formular but a different arrangement of atoms in space
Electrophile
electron pair acceptor
Nucleophile
electron pair doner
Substitution Reaction
When an atom or group of atoms is replaced with a different atom or group of atoms
Hydrocarbon
Contains hydrogen and carbon only
Aliphatic
A compound containing carbon and hydrogen joined together in straight or branched chains or non-aromatic rings
Alicyclic
An aliphatic compound arranged in non-aromatic rings with or without side chains
Aromatic
A compound containing a benzene ring
Functional group
A group of atoms responsible for the characteristic reactions of a compound
E/Z isomerism
An example of stereoisomerism
Occurs due to restricted rotation about C=C
Occurs if the groups attached to each carbon atom of the C=C group are different
cis/trans isomerism
A special type of e/z isomerism in which two of the substituent groups attached to each carbon atoms of the C=C bond are the same
Oxidation
loss of electrons
Reduction
gain of electrons
Isotope
Atoms of the same elements with the same number of protons but a different number of neutrons
Permanent dipole
The attractive force between two neighbouring molecules
Catalyst
Changes the rate of reaction but is chemically unchanged by lowering the activation energy and providing an alternative reaction pathway
Activation energy
Minimum energy required for the reaction to start
London forces
A temporary attractive force due to the formation of temporary
dipoles in a nonpolar molecule.
Electronegativity
The ability of an atom in a covalent bond to attract the shared pair of bonding electrons towards itself
Biodegradable
Can be broken down by microbes
Photodegradable
Can be broken down by light
First ionisation energy
The energy required to remove one mole of electrons from one mole of gaseous atoms to form one mole of gaseous 1+ ions
Periodicity
A repeating trend in physical and chemical properties across the periods of the periodic table
Acid
A substance that donates protons when dissolved in water
Disproportionation
When the same element is oxidised and reduced in a reaction
Redox reaction
When oxidation and reduction happen in the same reaction
Oxidation number
Total number of electrons an atom gains or loses to form a chemical bond
Displacement reaction
The more reactive halogen will act as the oxidising agent and oxidise and displace the less reactive halogen
Saturated
single carbon-carbon bonds only
Unsaturated
the presence of multiple carbon-carbon bonds, including C=C , C≡C and aromatic rings
