Thermodynamics Flashcards
What is lattice enthalpy?
The enthalpy change when 1 mole of a solid ionic lattice forms from its gaseous ions under standard conditions
More energy released, the stronger the bonds are
Define lattice enthalpy of formation
The enthalpy change when 1 mole of solid ionic lattice is formed from its gaseous ions under standard conditions
Define standard enthalpy of formation
The enthalpy change when 1 mole of a compound is formed from its elements under standard conditions.
Define standard enthalpy of atomisation
The enthalpy change which accompanies the formation of 1 mole of gaseous atoms from the element in its standard state under standard conditions
Define the fist ionisation energy
The enthalpy change when 1 mole of gaseous atoms is converted into a mole of gaseous iona each with a single positive charge
Define second ionisation energy
The enthalpy change when a mole of electrons I lost from 1 mole of a singly positively charged ion to form 1 mole of 2+ ions
Define the first electron affinity
The enthalpy change when 1 mole of gaseous atoms is converted to 1 mole of gaseous ions each with a single negative charge
Define the second electron affinity
The enthalpy change when 1 mole of electrons is added to 1 mole of gaseous ions each with a single negative change to form ions each with 2 negative charges
Define lattice enthalpy of dissociation
The enthalpy change when 1 mole of solid ionic compound is dissociated into its gaseous ions
Define enthalpy of hydration
The standard enthalpy change when 1 mole of gaseous ions is converted into 1 mole of aqueous ions
Define enthalpy of solution
The enthalpy change when one mole of dilute dissolved completely in sufficient solvent to form a solution where the ions are far enough apart to not interact with one another.
Define the mean bond enthalpy
The enthalpy change when 1 mole of gaseous molecules each breaks a covalent bond to form 2 free radicals averaged over a range of compounds
What are he stages in a born haber cycle?
- Atomisation of elements
- Ionisation if elements
- Electron affinity of elements
- Lattice enthalpy
What is the formula for charge density?
Charge density = charge/size
What happens when we dissolve a solid?
First the ionic solid is broken down.
Then free ions become part of the solution (hydration)
This has an enthalpy change (enthalpy change of solution)
This can be an exo or endothermic reaction.