OCR A Chemistry F325 Definitions 4.5 / 5 based on 3 ratings ? ChemistryF325: Equilibria, Energetics and ElementsA2/A-levelOCR Created by: Brandon LoweCreated on: 23-04-14 12:07 Rate of reaction The change in concentration of a reactant or product per unit time. 1 of 25 Order of a reactant The power of the concentration of a particular reactant to which the rate of reaction is directly proportional. 2 of 25 Rate constant A coefficient of proportionality relating the rate of a chemical reaction at a given temperature to the product of the concentrations of reactants. 3 of 25 Half-life The time it takes for the concentration of a particular reactant to reduce by half. 4 of 25 Rate-determining step The slowest step in a reaction mechanism that limits the rate of the overall reaction. 5 of 25 pH pH=-log[H+] 6 of 25 [H+] [H+]=10^(-pH) 7 of 25 Ionic product of water, Kw Kw=[H+][OH-] 8 of 25 Buffer solution A system that minimises pH changes on addition of small amounts of an acid or a base. 9 of 25 Enthalpy change of neutralisation The energy change that occurs when solutions of an acid and an alkali react together under standard conditions to produce one mole of water. 10 of 25 Lattice enthalpy The enthalpy change that accompanies the formation of one mole of an ionic compound from its gaseous ions under standard conditions. 11 of 25 Enthalpy change of solution The enthalpy change of solution is the enthalpy change when one mole of an ionic substance dissolves in water. 12 of 25 Enthalpy change of hydration The enthalpy change when one mole of gaseous ions dissolve in water. 13 of 25 Free energy change ΔG = ΔH - TΔS where ΔG = free energy change, ΔH = enthalpy change, T = absolute temperature, and ΔS = entropy change. 14 of 25 Redox A process in which one species is reduced and other oxidised. 15 of 25 Oxidation number A number assigned to an element that represents the number of electrons lost, or gained, by an atom of that element. 16 of 25 Half-reaction The oxidation or reduction component of a redox reaction. 17 of 25 Oxidising agent A species that brings about oxidation by being reduced. 18 of 25 Reducing agent A species that brings about reduction by being oxidised. 19 of 25 Standard electrode potential The e.m.f. of a half cell compared with the standard hydrogen half-cell at 298K, a pressure of 100kPa and with a solution concentration of 1 mol/dm^3. 20 of 25 Transition element A d-block element that can form an ion with an incomplete d sub-shell. 21 of 25 Ligand An ion or molecule attached to a metal ion by coordinate bonding. 22 of 25 Complex ion An ion surrounded by ligands. 23 of 25 Coordination number The number of ligands bonded to the central ion in a complex ion. 24 of 25 Bidentate ligand A ligand that forms two coordinate bonds. 25 of 25
Comments
No comments have yet been made