Energetics Flashcards
1.
Hess’s Law
The enthalpy change for a chemical reaction is the same, regardless of the route taken from reactants to products.
Standard Enthalpy of Formation, ∆Hɵf
The enthalpy change when one mole of a compound is formed from its elements under standard conditions, all reactants and products in their standard states.
Standard Enthalpy of Combustion, ∆Hɵc
The enthalpy change when one mole of a compound is completely burned in oxygen under standard conditions, all reactants and products in their standard states.
Standard Enthalpy of Atomisation, ∆Hɵat
The enthalpy change when one mole of gaseous atoms is formed from an element in its standard state.
First Ionisation Enthalpy, 1st∆Hɵi
The standard enthalpy change when one mole of electrons is removed from one mole of gaseous atoms to give one mole of gaseous ions each with a single positive charge.
Second Ionisation Enthalpy, 2nd∆Hɵi
The standard enthalpy change when one mole of electrons is removed from one mole of gaseous 1+ ions to give one mole of gaseous ions each with a 2+ charge.
First Electron Affinity, 1st∆Hɵae
The standard enthalpy change when one mole of gaseous atoms is converted into a mole of gaseous ions, each with a single negative charge under standard conditions.
Second Electron Affinity, 2nd∆Hɵae
The standard enthalpy change when one mole of electrons is added to a mole of gaseous ions each with a single negative charge, to form a mole of ions each with a two negative charge.
Lattice Formation Enthalpy ΔHLFΘ
The standard enthalpy change when one mole of solid ionic compound is formed from its gaseous ions.
Lattice Dissociation Enthalpy ΔHLDΘ
The standard enthalpy change when one mole of solid ionic compound dissociates into its gaseous ions.
Standard Enthalpy of Hydration ΔHhydΘ
The standard enthalpy change when one mole of gaseous ions is converted into one mole of aqueous ions.
Standard Enthalpy of Solution ΔHsolΘ
The standard enthalpy change when one mole of solute dissolves in enough solvent to form a solution in which the ions are far enough apart not to interact with each other.
Mean Bond Enthalpy ΔHΘ
The enthalpy change when one mole of gaseous molecules each break a covalent bond to form two free radicals, averaged over a range of compounds.
Define enthalpy change
The change in heat energy at constant pressure
What are standard conditions?
100 kPa or 1 atmosphere (1atm.) pressure and a temperature of 298K (25 degrees C)
