Definitions HL only Flashcards
definition of a ligand [2]
a ligand is an ion or molecule that donates a pair of electrons [1] to a metal atom or ion in forming a coordination complex [1]. Ligands are Lewis bases.
definition of standard state [1]
a standard state of an element or compound is its most stable state under specified conditions. For example, standard state of H2O at 298K is H2O(l)
definition of standard enthalpy change of formation (dHf)[1]
the standard enthalpy change of formation is the enthalpy change on the formation of one mole of a compound from its elements in their standard states under standard conditions.
definition of standard enthalpy change of combustion (dHc) [1]
the enthalpy change of combustion is the enthalpy change on the complete combustion of one mole of the compound in its standard state in excess oxygen under standard conditions.
definition of lattice enthalpy
lattice enthalpy is the enthalpy change which occurs on the formation of 1 mole of ionic compound from its isolated ions in their gaseous state. This is exothermic. [dH is negative). lattice enthalpy can also be defined as the enthalpy change on separating 1 mole of ionic compound into its separate gaseous ions. This is endothermic. (dH is positive).
definition of electron affinity [2]
electron affinity is the energy change when a gaseous atom [1] gains an electron to form a negative ion [1].
definition of rate constant
the rate constant k is the constant in the rate equation: rate = k[A]m[B]n. The unit varies depending on the order of the reaction.
order of reaction [2]
the order of the reaction with respect to a reactant is the power to which its concentration is raised in the rate equation[1]. The overall order of the reaction is the sum of the orders with respect to the individual reactants. [1]
definition of oxidising agents
oxidising agents accept electrons whilst oxidising other substances.
definition of reducing agents
reducing agents donate electrons to reduce other substances .
definition of standard electrode potential[4]
the standard electrode potential of a half-cell is its electrode potential relative to a hydrogen half-cell measured under standard conditions [1] which are atmospheric pressure [1], 298 K [1], 1 mole/dm3 [1]concentration
