Chem Unit 2 definitions (syllabus)

Change in concentration of a reactant or product per unit time

The power to which the concentration of the reactant is raised in the rate equation.

The constant that links the rate of reaction with the concentrations of the reactants raised to the power of their orders in the rate equation

The half life of a reactant is the time taken for the concentration of that reactant to reduce by half.

The slowest step in the reaction mechanism of a multi - step reaction.

A proton donor

A proton acceptor

A pair of two species that transform into each other by gain or loss of a proton.

A strong acid almost completely dissociates, a weak acid partially dissociates

System that minimises pH changes on addition of small amounts of an acid or a base

The enthalpy change that accompanies the formation of one mole of an ionic compound from its gaseous ions under standard conditions.

Enthalpy change that takes place when one mole of a compound is completely dissolved in water under standard conditions.

Standard enthalpy change that takes place when one mole of isolated gaseous ions is dissolved in water forming one mole of aqueous ions under standard conditions

The quantitative measure of disorder in a system.

A reaction in which both oxidation and reduction take place

A measure of the number of electrons that an atom uses to bond with atoms of another element.

A reagent that oxidises another species (takes electrons)

A reagent that reduces another species (gives electrons)

The emf of a half cell compared with a standard hydrogen half cell measure at 298K with solution concentrations of 1mol/dm³ and a gas pressure of 100kpa

A d-block element which forms an ion with an incomplete d sub - shell

A molecule or ion that can donate a pair of electrons with the transition metal ion to form a coordinate bond.

A transition metal ion bonded to one or more ligands by coordinate bonds (dative covalent bonds)

The total number of coordinate bonds formed between the central metal ion and any ligands.

When a ligand can donate two lone pairs of electrons to the central metal ion to form two coordinate bonds.

A reaction in which one ligand in a complex ion is replaced by another ligand.

The equilibrium constant for an equilibrium existing between a transition metal ion surrounded by water ligands and the complex formed when the same ion has undergone a ligand substitution reaction.

Enthalpy change that occurs for the formation of 1 mole H2O from reaction of an acid with an alkali/base