17.2 born haber cycle

Question 1

What is a Born-Haber cycle

Answer 1

A thermochemical cycle that includes all the enthalpy changes involved in forming an ionic compound

They are constructed with the elements in their standard states (the elements all have a value of zero here)

Question 2

What size elements lead to the largest lattice enthalpies

What about the smallest

Answer 2

The smaller each ion is, the stronger the value
eg Li+ and F-

The larger the ions are, the opposite charges do not approach each other as closely, so there is a lower lattice enthalpy

Question 3

How does the lattice enthalpy differ between ions with higher and lower charge densities eg 2+ compared to 1+

Answer 3

The higher the charge density (Eg Mg+ instead of Na+) , the lattice enthalpy increases with the size of the charge.

Because ions with double the charge will give out double the amount of energy when they come together