2.2 Flashcards
Hess’ law
If a reaction can take place by more than one route and the initial and final conditions are the same, the total enthalpy change is the same for each route
Standard enthalpy change of formation
The enthalpy change that takes place when one mole of a compound is formed is formed from its constituent elements in their standard states under standard conditions
Enthalpy change of atomisation
The enthalpy change that takes place when one mole of gaseous atoms forms from the element in its standard state
The first ionisation energy
The enthalpy change accompanying the removal of one electron from each electron in one mole of gaseous atoms to form one mole of 1+ ions
First electron affinity
The enthalpy change accompanying the addition of one electron to each atom in one mole of gaseous atoms To form one mole of gaseous 1- ion
Lattice enthalpy
The enthalpy change that accompanies the formation of one mole of an Joni compound from its gaseous ions under standard conditions
Standard enthalpy change of solution
The enthalpy change that takes place when one mole of a compound is completely dissolved in water under standard conditions
Standard enthalpy change of hydration
The enthalpy change that takes place when one mole of isolated gaseous ions is dissolved in water forming one mole of aqueous ions under standard conditions
Entropy, S
The degree of disorder in a system
Standard entropy change of reaction
The entropy change that accompanies a reaction in the molar quantities expressed in a chemical equation under standard conditions, reactants and products in standard states
Free energy change
The balance between enthalpy, entropy and temperature for a process.
Standard electrode potential of a half cell
The e.m.f of a half cell compared with a standard hydrogen half cell, measured at 298K with solution concentration of 1 moldm and gas pressure 100 kPA
