Lattice Enthalpy

Question 1

What are 2 factors that affect lattice enthalpy?

Answer 1

Ionic size
Highly-charged ions

Question 2

How does ionic size affect lattice enthalpy?

Answer 2

Lattice enthalpy becomes less exothermic and less negative as size of negative ions increases, meaning weaker attraction between ions and weaker ionic bonding

Question 3

How does charge affect lattice enthalpy?

Answer 3

Charge increases and produces greater attraction between positive and negative ions. Ionic radius decrease resulting in ions in lattice being closer together

Question 4

How does polarisation affect actual experimental enthalpies?

Answer 4

The more the e- cloud is distorted toward small cation, the more covalent character the compound shows - causes bond between ions to be stronger, increasing(more positive) actual experimental enthalpies

Question 5

What is the 2nd law of thermodynamics?

Answer 5

All chemical and physical changes involve an overall increase in entropy