Enthalpy, Entropy and Free Energy

Cards (14)

Enthalpy of atomisation
The enthalpy change when 1 mole of gaseous atoms is formed from the elements in their standard states
Enthalpy of ionisation
The enthalpy change when one mole of gaseous atoms have their electrons removed to form one mole of gaseous 1+ ions
Enthalpy of electron affinity
The enthalpy change when one mole of electrons is added to a mole of gaseous atoms to form one mole of gaseous 1- ions
Lattice enthalpy 
The enthalpy change when one mole of an ionic compound is formed from its gaseous ions under standard conditions
Enthalpy of formation
The enthalpy change when one mole of a compound is formed from its constituent elements in their standard states under standard conditions
Enthalpy of solution
The enthalpy change when one mole of an ionic compound is dissolved in water under standard conditions
Enthalpy of hydration
The enthalpy change when one mole of gaseous ions is dissolved to create an infinitely dilute solution
Entropy
A measure of disorder (J k- mol-)
What causes high entropy in a chemical reaction?
Gases being formed or more molecules being formed
Entropy sign
How is free Gibbs energy calculated? 
ΔG=ΔH-TxΔS
When does a reaction become feasible according to Gibbs free energy?
0 degrees
What results in higher entropy?
More moles or more gases producing more disorder
Why are some reactions not feasible at any temperature?
ΔH is positive
ΔS is negative
therefore ΔG will never be negative