Inorganic Chem: Energetics definitions

Exothermic

energy released from the system to the surroundings as heat energy

endothermic

energy absorbed from the surroundings to the systemas heat energy

the system

the chemicals in the reaction mixture

delta H

enthalpy change

enthalpy change

the energy transferred between the system and its surroundings when the change happens at constant pressureand is often measured in joules or calories.

E_A

activation energy - the minimum energy required for a chemical reaction to occur.

bond enthalpy

bond energy, which is the energy needed to break one mole of a bond in a gaseous molecule forming gaseous atoms

standard enthalpy change of neutralisation

the enthalpy change when an acid and an alkali react together under standard conditions to form one mole of water

standard conditions

• a pressure of 100kPa

  • a specified temperature (if this is not specified it may be taken as 298k)

standard enthalpy of combustion

the enthalpy change when one mole of a substance is burned completely in air or oxygen under standard conditions.

standard enthalpy change of formation

the enthalpy change when one mole of a compound is formed from its elements in their normal physical states under standard conditions.

standard enthalpy of reaction

enthalpy change when the molar quantities of reagents shown in a given equation react according to that equation under standard conditions

lattice energy

energy released when one mole of a solid ionic lattice is formed from its gaseous ions

1st IE

energy required to remove one electron from each atom in 1 mole of gaseous atoms