Inorganic Lecture 7

Inorganic Lecture 7 - Lecture 7 Lattice Energy Coulombic...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 7 Lattice Energy Coulombic Interactions Born Forces Madelung Constants Born-Haber Cycle
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Lattice Energy Where does the stability of Ionic compounds arise from? Ionic solids adopt, for the most part, close- packed structures in order to maximize the number of contacts between oppositely charged ions while simultaneously keeping ions of the same sign as far apart as possible In an ionic solid, unlike ions attract each other and energy is released when the “ion pair” is formed
Background image of page 2
Lattice Energy Δ U(0K), lattice energy, of an ionic compound is the change in internal energy that accompanies the formation of one mole of the solid from its constituent gas-phase ions at 0K M n+ (g) + nX - (g) MX n (s) Na + (g) + Cl - (g) NaCl(s) In this model we consider the ions as “point charges” There is no account for covalent bonding
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Components of Lattice Energy 1. Coulombic (electrostatic) attraction 2. Coulombic repulsion 3. Born Repulsion 4. Dispersion Energy 5. Zero-point Energy The first three terms are most important
Background image of page 4
Internal Energy First we start with the change in internal energy within an isolated pair of ions Δ U = - |z + | |z - | e 2 4 πε o r Δ U = change in internal energy (joules) |z + | = the absolute value of the charge of the cation
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 18

Inorganic Lecture 7 - Lecture 7 Lattice Energy Coulombic...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online