energetics 1 - definitions Flashcards
Solution enthalpy
enthalpy change one mole of solid dissolves in a large excess of water so ions no longer interact under standard conditions
Hydration enthalpy
the enthalpy change when one mole of gaseous ions dissolves in water to form one mole of aqueous ion under standard conditions
Lattice Dissociation Enthalpy
The enthalpy change when 1 mole of a solid ionic compound is completely dissociated into its gaseous ions under standard conditions
Lattice formation enthalpy
Enthalpy change when 1 mole of a solid ionic
compound is formed from its gaseous ions under standard conditions
Atomisation enthalpy
The energy required for the formation of a mole of gaseous atoms under standard conditions
enthalpy of combustion
the enthalpy change for one mole of a substance to completely burn in o2 under standard conditions
enthalpy of formation
The enthalpy change when one mole of a substance is formed from its elements, with all substances in their standard states under standard conditions
Enthalpy of neutralisation
Enthalpy change when one mole of water is formed in a reaction between an acid and an alkali under standard conditions to form one 1 mole of water
enthalpy of reaction
the enthalpy of a quantity of substance to completely react in standard conditions in it’s standard state
bond enthalpy equation
bonds broken - bonds formed
(reactants - products)
factors affecting hydration enthalpy
- ionic radius
- ionic charge
e.g = charge density
factors affecting lattice enthalpy:
- charge density
- size of ion (leads to greater distortion)
more distortion = more covalent character = greater difference in theoretical vs experimental values
experimental vs theoretical: combustion
- heat loss to surroundings
- incomplete reaction
- water evaporated
IF SAYS STANDARD (then standard conditions)
experimental vs theoretical: bond enthalpy
- no. of moles
- mean values used
