F325 Past Papers

Question 1

What is lattice enthalpy?

Answer 1

(The enthalpy change that accompanies) the formation of one mole of a(n ionic) compound from its gaseous ions
(under standard conditions).

Question 2

Why is the enthalpy change of hydration exothermic?

Answer 2

Hydration involves bond forming.

Question 3

The enthalpy change of hydration of magnesium ions is more exothermic than the enthalpy
change of hydration of calcium ions.
Explain why.

Answer 3

Magnesium ion has a greater charge density, so magnesium ions have a stronger attracction to H20.