Module 3 - Definitions Flashcards
What is average bond enthalpy?
Average enthalpy change when one mole of bonds of gaseous covalent bonds is broken.
What is first ionisation energy?
The first ionisation energy is the energy needed to remove an electron from each atom in one mole of gaseous atoms.
What is the standard enthalpy change of formation?
The enthalpy change when 1 mole of the compound is formed from its elements under standard conditions (298K and 100kpa), all reactants and products being in their standard states.
Symbol ∆fH.
What is the standard enthalpy change of combustion?
The enthalpy change that occurs when one mole of a substance is combusted completely in oxygen under standard conditions. (298K and 100kPa), all reactants and products being in their standard states.
Symbol ∆cH
What is the enthalpy change of neutralisation?
The standard enthalpy change of neutralisation is the enthalpy change when solutions of an acid and an alkali react together under standard conditions to produce 1 mole of water.
Symbol ∆neutH
What is a base?
A H+ ion acceptor.
What is le Chatelier’s principle?
When a system in equilibrium is subjected to an external change the system reajusts itself to minimise the effect of that change.
