Energetics

• Enthalpy change - the heat energy change measured under conditions of constant pressure
• Enthalpy change of formation - the enthalpy change when one mole of a compound is formed from its constituent elements with all reactants and products in their standard states under standard conditions
• Enthalpy change of combustion - the enthalpy change when one mole of a substance is burned completely in excess oxygen with all reactants and products in their standard states under standard conditions
• Enthalpy change of reaction - the enthalpy change when substances react under standard conditions in quantities given by the equation for the reaction
• Standard enthalpy of neutralisation - the enthalpy change when one mole of water is formed from its ions in dilute solution
• bond enthalpy - the energy required to break one mole of a covalent bond measured in the gaseous state
• Mean bond enthalpy - the energy required to break one mole of a covalent bond measured in the gaseous state averaged across many compounds containing the bond
• Hess's Law - the enthalpy change of a reaction is independent of the route taken.