Energetics II (13) Flashcards
(9 cards)
1
Q
Define standard enthalpy change of atomisation (1)
A
- Change in enthalpy when one mole of gaseous atoms is formed from the element under standard conditions
2
Q
Define standard enthalpy change of hydration enthalpy (1)
A
- enthalpy change when one mole of gaseous ions dissolve in sufficient water to give an infinitely dilute solution under standard conditions
3
Q
Define standard enthalpy change of solution (1)
A
- enthalpy change when one mole of an ionic substance dissolves in water to give an infinitely dilute solution under standard conditions
4
Q
Define standard enthalpy change of ionisation (1)
A
- enthalpy required to remove one mole of electrons from one mole of gaseous ions under standard conditions
5
Q
Define standard enthalpy change of electron affinity (1)
A
- enthalpy change when one mole of gaseous atoms accepts one mole of electrons to become one mole of gaseous ions under standard conditions
6
Q
Define standard enthalpy change of lattice enthalpy (2)
A
- (formation) enthalpy change when one mole of an ionic lattice is formed from its isolated (start infinitely apart) gaseous ions - highly exothermic
- (dissociation) enthalpy change when one mole of an ionic lattice dissociates into its isolated gaseous ions - highly endothermic
7
Q
Explain the factors that affect the lattice enthalpy (formation) (2)
A
- A higher total charge on ions increases lattice enthalpy (more exothermic)
- A larger distance between the centres of the cation to the adjacent anion (sum of ionic radii) decreases lattice enthalpy (less exothermic)
8
Q
Explain the factors that affect the hydration enthalpy (2)
A
- A higher total charge on ions increases hydration enthalpy (more exothermic)
- A larger ionic radii of ions decreases hydration enthalpy (less exothermic)
9
Q
Define entropy (2)
A
- entropy is a measure of the disorder of particles
2. entropy always increases in a thermodynamic system
