Thermodynamics Flashcards
What does a negative free energy change tell us?
The process is spontaneous (feasible).
Define enthalpy change
The heat change at constant pressure
Define enthalpy of atomisation of an element.
The enthalpy change when one mole of gaseous atoms is formed from the element in its standard state
Define enthalpy of hydration.
The standard enthalpy change when water molecules surround one mole of gaseous ions.
Define enthalpy of solution.
The standard enthalpy change when one mole of an ionic solid dissolves completely in sufficient water to form a solution in which the ions are far enough apart not to interact with each other
Define first electron affinity.
The standard enthalpy change when a mole of gaseous atoms is converted to a mole of gaseous ions each with a single negative charge.
Define first ionisation energy.
The standard enthalpy change when one mole of gaseous atoms is converted into a mole of gaseous ions each with a single positive charge.
Define lattice dissociation enthalpy.
The standard enthalpy change when one mole of solid ionic compound is broken up into its free gaseous ions.
Define lattice formation enthalpy.
The standard enthalpy change when one mole of solid ionic compound is formed from its free gaseous ions.
Define mean bond enthalpy.
The enthalpy change when one mole of covalent bonds is broken, with all species in the gaseous state, average over a range of different compounds.
Define second electron affinity.
The standard 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 a double negative charge.
Define second ionisation energy.
The standard enthalpy change when one mole of gaseous unipositive ions is converted into a mole of gaseous ions each with a double positive charge.
Define standard enthalpy of atomisation of a compound.
The enthalpy change when one mole of a compound in its standard state is converted into its free gaseous atoms.
Define standard enthalpy of combustion.
The enthalpy change when one mole of a substance is completely burned in oxygen under standard conditions, all reactants and products being in their standard states.
Define standard enthalpy of formation.
The enthalpy change when one mole of a substance is produced from its constituent elements under standard conditions, all reactants and products being in their standard states.
