Energetics II

Question 1

what is lattice energy?

Answer 1

the energy change when one mole of an ionic solid is formed from its gaseous ions under standard conditions (298K 100kPa)

Question 2

what is enthalpy change of atomisation, ΔatH?

Answer 2

Enthalpy change when 1 mole of gaseous atoms is formed from the elements in its standard states. Always endothermic.

Question 3

what is electron affinity?

Answer 3

the energy change when each atom in one mole of atoms in the gaseous state gains an electron to form a -1 ion

Question 4

what is lattice energy a measure of?

Answer 4

ionic bond strength

Question 5

what is ‘enthalpy change of solution, ΔsolH?

Answer 5

enthalpy change when one mole of solute dissolves in water

Question 6

what is ‘enthalpy
change of hydration, ΔhydH’?

Answer 6

enthalpy change when one mole of gaseous ions dissolves in water

Question 7

if lattice energy is more negative what does this imply?

Answer 7

the ionic bonding of the compound is strong

Question 8

what is the unit for entropy?

Answer 8

K-1 mol-1

Question 9

what is the formula for entropy change in the surroundings?

Answer 9

∆ S surroundings = -∆sol H/T

Question 10

what is the formula for ΔStotal?

Answer 10

ΔS total = ΔS system + ΔS surroundings