Thermodynamics Flashcards
What are the 2 types of lattice enthalpy
Latice enthalpy of formation and dissociation
What is the difference between lattice enthalpy of formation and dissociation
Lattice enthalpy of dissociation is positive
Lattice enthalpy of formation is negative
What is the lattice enthalpy of formation
The standard enthalpy change when one mole of solid ionic compound is formed from its gaseous ions.
What is the lattice enthalpy of dissociation
The standard enthalpy change when one mole of solid ionic compound dissociated into its gaseous ions.
What is ionisation energy
The standard enthalpy change when one mole of gaseous atoms is converted into a mole of gaseous ions each with a single positive charge.
What is the enthalpy of formation
The enthalpy change when one mole of a compound is formed from its constituent elements under standard conditions, all reactants and products in their standard states.
What is the enthalpy of atomisation
The enthalpy change which accompanies the formation of one mole of gaseous atoms from the element in its standard state under standard conditions.
Bond dissociation enthalpy vs Enthalpy of atomisation
Bond dissociation - one mole of a bond is broken to give separated ions
Atomisation - Enthalpy change accompanying the formation of 1 mole of gaseous ions
Therefore the ΔA in Cl will be half the enthalpy of bond dissociation energy
What is mean bond enthalpy
Enthalpy change to break 1 mol of bonds
Averaged over a range of compounds
What is electron affinity
The standard enthalpy change when a mole of gaseous atoms is converted to a mole of gaseous ions, each with a single negative charge.
What is enthalpy of hydration
The standard enthalpy change when water molecules surround one mole of gaseous ions.
How do you edit a born haber cycle if atoms are diatomic
Multiply their enthalpies by 2
What affects how large the lattice enthalpy of formation is
The size of the positive and negative ions
The bigger the ions, the smaller the lattice enthalpies
Why is ΔΗ not sufficient for explaining feasible change
Depends on the sign of ΔG. If it is negative, the reaction is feasible
What is the symbol for entropy
ΔS