5.2.1: Lattice enthalpy

Question 1

Define lattice enthalpy

Answer 1

Formation of 1 mole of ionic lattice from

gaseous ions under standard conditions

Question 2

What does a more exothermic lattice enthalpy mean?

Answer 2

More exothermic = more stronger ionic

bonds

Question 3

Why is it not possible to measure lattice enthalpy

directly?

Answer 3

It is not possible to form 1 mole of ionic solid from its gaseous ions

Question 4

Define enthalpy change of solution

Answer 4

Enthalpy change that takes place when 1
mole of a solute is completely dissolved
in water under standard conditions

Question 5

Define enthalpy change of hydration

Answer 5

The enthalpy change that takes place
when dissolving one mole of gaseous
ions in water

Question 6

What are the factors that impact the size of lattice

enthalpy?

Answer 6

● Size of ions involved
● Charges on the ions
● Ionic bond strength

Question 7

Which ions have more negative lattice enthalpy

values? smaller / larger ions? Why?

Answer 7

Smaller ions because they can get closer

hence more stronger attraction

Question 8

Describe hydration

Answer 8

When a ionic lattice is broken the ions become part of the solution
Positive ions get attracted towards slightly negative oxygen and negative ions get attracted towards slightly positive hydrogen

Question 9

What are the factors that impact the magnitude of

the enthalpy of hydration?

Answer 9

● Size of the ion

● Charge on the ions