Thermodynamics - Enthalpy change Flashcards
The standard molar enthalpy of formation
Enthalpy change when one mole of a compound is formed from its constituent elements under standard conditions, all reactants and products in their standard states
The standard molar enthalpy change of combustion
Enthalpy change when one mole of substance is completely burnt in oxygen
The standard enthalpy of atomisation
Enthalpy change when one mole of gaseous atoms is formed from an element in its standard state under standard conditions
Atomisation of an element OR compound e.g. NaCl (s) -> Na(g) + Cl (g)
First ionisation energy
Standard enthalpy change when one mole of gaseous atoms is converted into a mole of gaseous ions each with a single positive charge
Second ionisation energy
Standard enthalpy change when one mole of gaseous 1+ ions is converted into a mole of gaseous 2+ ions
The first electron affinity
Standard enthalpy change when a mole of gaseous is converted to a mole of gaseous 1- ions
Second electron affinity
Enthalpy change when a mole of electrons is added to a mole of gaseous ions each with a single negative charge to form ions each with two negative charges
Lattice enthalpy of formation
Standard enthalpy change when one mole of solid ionic compound is formed from its gaseous ions
Lattice enthalpy of dissociation
Standard enthalpy change when one mole of solid ionic compound dissociated into its gaseous ions (calculated not measured)
Enthalpy of hydration
Standard enthalpy change when water molecules surround one mole of gaseous ions, forming one mole of aqueous ions
Enthalpy of solution
Standard enthalpy change when one mole of solute dissolves completely in sufficient solvent to form a solution in which the molecules or ions are far enough apart not to interact with each other
Mean bond enthalpy
Enthalpy change when one mole of gaseous molecules each breaks a covalent bond to form two free radicals, averaged over a range of compounds
