ieb chem definitions Flashcards
ionisation
the reaction of a molecular substance with water to produce ions
oxidising agent
a substance that accepts electrons
(is reduced)
reducing agent
a substance that donates electrons
(is oxidised)
salt
a substance in which the hydrogen of an acid has been replaced by a cation
heat of reaction
the net change of chemical potential energy of a system
ampholyte
amphoretic
amphiprotic
a substance that can act as either an acid or a base
base
proton acceptor
reaction rate
the change in concentration per unit time of either a reactant or a product
dissociation
the splitting of an ionic compound into its ions
redox reaction
a reaction involving the transfer of electrons
exothermic reaction
reactions which transform chemical potential energy into thermal energy (🔺H < 0)
catalyst
a substance that increases the rate of the reaction but remains unchanged at the end of the reaction
activated complex
a high energy, unstable, temporary transition state between the reactants and the products
endothermic reaction
reactions which transform thermal energy into chemical potential energy (🔺H > 0)
le châtelier’s principle
when an external stress (change in pressure, temperature, or concentration) is applied to a system in dynamic chemical equilibrium, the equilibrium point changes so as to counteract the stress
oxidation
loss of electrons
reduction
gain of electrons
molar mass
the mass (in grams) of one mole of that substance
anode
the electrode where oxidation takes place
neutralisation/ equivalence point
the point where an acid and a base have reacted so that neither is in excess
standard solution
a solution of known concentration
weak base
a base that only dissociates partially in an aqueous solution
strong base
a base that dissociates almost completely in an aqueous solution
weak acid
an acid that only ionises partially in an aqueous solution
strong acid
an acid that ionises almost completely in an aqueous solution
cathode
the electrode where reduction takes place
electrolyte
a substance that can conduct electricity by forming free ions when molten or dissolved in a solution
open system
a system in which both energy and matter can be exchanged between the system and its surroundings
closed system
a system in which mass is conserved inside the system but energy can enter or leave the system freely
activation energy
the minimum energy required to start a chemical reaction
acid
proton donor
hydrolysis
a reaction of an ion from a salt with water
molar concentration
the amount of solute per unit volume of solution
electronegativity
a measure of the tendency of an atom to attract a bonding pair of electrons
hydrocarbon
compound containing only carbon and hydrogen atoms
saturated compound
compound in which all the bonds between carbon atoms are single bonds
unsaturated compound
compound in which there is at least one double/triple bond between carbon atoms
functional group
an atom or group of atoms that form the centre of chemical activity in the molecule
homologous series
series of similar compounds which have the same functional group and have the same general formula in which each member differs from the previous one by a single CH2 unit
structural isomers
compounds having the same molecular formula but different structural formulae
