enthalpy changes Flashcards
exothermic
bond forming releasing energy
endothermic
bond breaking absorbing energy
which products are energetically more stable
more exothermic, lower energy level
enthalpy change of reaction
energy change in a chemical reaction when molar quantities of reactants stated in the chemical equation react under 1 bar 298K
enthalpy change of formation
energy change when 1 mole of pure substance in specified state formed from its constituent elements in their standard states under 1 bar and 298K
enthalpy change of combustion
energy released when 1 mole of a substance is completely burnt in excess oxygen under 1 bar and 298K
enthalpy change of neutralisation
between acid and base is the energy change when acid and base react and form 1 mole of water under 1 bar and 298K
enthalpy change of hydration
energy released when 1 mole of gaseous ion is hydrated under 1 bar and 298K
enthalpy change of solution
energy change when 1 mole of substance is completely dissolved in a solvent to form an infinitely dilute solution under 1 bar 298K
lattice energy
energy released when 1 mole of solid ionic compound is formed from its constituent gaseous ions under 1 bar 298k
bond dissociation energy
energy required to break 1 mole of particular X-Y bond in a particular compound in gaseous state
bond energy
average energy required to break 1 mole of the X-Y bonds in the gaseous state
ionisation energy (1st)
energy required to remove 1 mole of electrons from 1 mole of gaseous atoms to form 1 mole of singly positively charged gaseous ions
electron affinity
energy change when 1 mole og gaseous atoms acquires 1 mole of electrons to form a singly negatively charged ion
enthalpy change of atomisation
energy absorbed when 1 mole of gaseous atoms is formed from the element under standard conditions
