Lattice Enthalpy

Question 1

What is lattice enthalpy?

Answer 1

When ionic compounds form regular structures called giant ionic lattices where the positive and negative ions are held together by electrostatic attractions.
When gaseous ions combine to make a solid ionic lattice energy is given out (lattice enthalpy)

Question 2

Define lattice enthalpy

Answer 2

When 1 mole of solid ionic compound is formed from its gaseous ions

Question 3

Is lattice formation endothermic or exothermic?

Answer 3

Exothermic because energy is released when new bonds form

Question 4

How do you know how strong the ionic bonding is?

Answer 4

The more negative the lattice enthalpy the stronger the bonding

Question 5

What two factors affect lattice enthalpy?

Answer 5

Ionic Charge

Ionic Radius

Question 6

How does ionic charge affect lattice enthalpy?

Answer 6

The higher the charge on the ions, the stronger the electrostatic attraction between the ions, so more energy will be released when a lattice forms. The more energy released means that the lattice enthalpy will be more negative. Thus meaning that lattice enthalpies with compounds with 2+ or 2- ions will be more negative than those with +1 or -1

Question 7

How does ionic radius affect lattice enthalpy?

Answer 7

The smaller the ionic radii of the ions, the higher the charge density of the ion. This means the electrostatic attraction between the ions is greater so the lattice enthalpy is more exothermic.

Question 8

How do you know the atomic radii of an element?

Answer 8

Atomic radii increases as you go down a group