AS Enthalpy, Born haber Flashcards
homogenous equilibrium
all species are in the same physical state
Heterogenous equilibrium
Species are in different states
Methods to determine equilibrium concentrations
- titration = remove portion to titrate from reaction mixture
- colorimeter = darker colour can mean higher conc and higher absorbance
standard enthalpy of neutralisation
The enthalpy change when an aqueous acid is neutralised by an aqueous base to form ONE MOLE OF H2O under standard conditions
Lattice enthalpy
Enthalpy change when one mole of an ionic lattice is formed from its constituent gaseous ions
Hydration enthalpy
Enthalpy change when one mole of a gaseous ion dissolves in excess water to give an infinitely dilute solution
Enthalpy of solution
Enthalpy change when one mole of a substance dissolves in an excess of solvent to give an infinitely dilute solution
Enthalpy
The heat content stored in a chemical system
Activation energy
The minimum energy required to start a reaction by the breaking of bonds
Hess’ Law
if a reaction can take place by more than one route and the initial and final conditions are the same, the total enthalpy change is the same for each route
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
Standard enthalpy change of formation
Enthalpy change when 1 mole of a compound is formed from its constituent elements in their standard states, under standard conditions
Standard enthalpy change of combustion
Enthalpy change when 1 mole of a substance (element or compound) reacts completely with oxygen under standard conditions
Standard enthalpy change of reaction
Enthalpy change that accompanies a reaction under standard conditions in the molar quantities expressed in a chemical equation, all reactants and products being in their standard states
