all Flashcards
Acid
a species that releases H+ ions in aqueous solution.
Acid dissociation constant Ka
The equilibrium constant that shows the extent of dissociation of a weak acid
for a weak acid: Ka = [H+(aq)] x [A-(aq)] / [HA(aq)]
Acid-base pairs
A pair of two species that transform into each other by gain or loss of a proton
Activation energy
the minimum energy required to start start a reaction by the braking of bonds
actual yield
the amount of product obtained from a reaction
addition polymerisation
formation of a very long molecular chain, by repeated addition reactions of many unsaturated alkene molecules
addition reaction
a reaction in which a reactant is added to an unsaturated molecule to form a saturated molecule
adsorption
the process that occures when or gas or liquid or solute is held to the surface of a solid. often used to speed up reactions
alicyclic
containing carbon atoms joined in a ring but is not aromatic
aliphatic
containing carbon atoms joined together in straight or branched chains
alkali
a type of base that when dissolved in water forms a hydroxide ion (OH-)
alkanes
general formula of Cn H2n+2
amount of substance
the quantity whose unit of the mole, used as a means of counting any species such as atoms, ions and molecules
anhydrous
containing no water molecules
anion
a negatively charged ion with more electrons than protons
Aromatic
cyclic hydrocarbons containing one or more benzene ring
atom economy
(sum of molar masses of the desired product)/(sum of molar masses of all products)
Atomic number
the number of protons in the nucleus of an atom
Atomic orbitals
a region of space around the nucleus that can hold up to two electrons with opposite spins
average bond enthalpy
the average enthalpy change that takes place when breaking, by homolytic fission, 1 mole of a given type of bond in the molecules of a gaseous species
Avogadro’s constant
the number of atoms per mole of carbon-12 (6.02x10^23)
base
a compound that neutralises an acid to form a salt
bond angles
the angle between two bonds at an element. notable ones include: tetrahedral, 109.5 pyramidal, 107 non-linear, 104.5 trigonal planar, 120 linear, 180
bond dissociation energy
the same as average bond enthalpy word for word…. but without average
bonded pair
a pair of electrons shared between two atoms to make a covalent bond
Bronsted-Lowry acid
a species that that is a proton, H+, donor
Bronsted-Lowry base
a species that is a proton acceptor
buffer solution
buffer solution
a system that minimises pH change on the addition of a small amount of acid or base
carbocation
an ion that contains a positively charged carbon atom
catalyst
a substance that increases the rate of a chemical reaction without being used up in the process; a catalyst provides an alternative route for the reaction with lower activation energy
cation
a positively charged ion with fewer electrons than protons
chain reaction
a reaction in which the propagation steps release new radicals that continue the reaction
cis-trans isomerism
a special type of E/Z isomerism in which there are two non-hydrogen groups and two hydrogen atoms around the C=C double bond: the cis isomer [Z isomer] has H atoms on each carbon on the same side. The trans isomer [E isomer] has the opposite.
closed system
A system isolated from its surroundings
