Chapter 12.3

Question 1

How do we calculate the U(ion pair)?

Answer 1

U(ion pair)= C X ((n^+ e)(n^- e)) / d

The symbol C represents a constant
d is the distance between the ion centers
e is the charge on an electron
the term n^+ e represents the charge on the cation in the ion pair
the term n^- e represent the charge on the negative ion.

Because n^+ e and n^- e have different signs, the energy calculated by this equation will have a negative value

Question 2

What is the U(ion pair) ?

Answer 2

U(ion pair) is the energy of attractive interaction between a pair of ions.

The important thing to notice is that the energy depend directly on the charge on the ions and inversely on the distance between them

Question 3

What is the lattice energy?

Answer 3

The energy of formation of one mole of a solid crystalline ionic compound when ions in the gas phase combines.

Question 4

For which type of compound we use the lattice enthalpy?

Answer 4

Ionic compounds

Question 5

For more highly charged ions, does ∆_lattice H has a larger negative value or larger positive value?

Answer 5

so ∆_lattice H has a larger negative value for more highly charged ions.