Transcript Ionic Bonding

Ionic Bonding
Kari Rogers
and
Emily Rankin
• Forming ionic bonds are usually exothermic
reactions
• If the charge is positive, an electron has been lost
• If the charge is negative, an electron has been
gained
• Electron transfers occur when atoms involved differ
in the attraction for electrons
• “NaCl is typical ionic compound because it
consists of a metal of low ionization
energy and a nonmetal with high affinity
for electrons” (pg. 278)
Lewis electron dot symbols
Arrow = transfer of Na electron to the Cl atom
Each ion has an octet of electrons
Octet = 8 electrons
Energies of ionic bond formation
Ionic compounds are stable
because the attraction between
ions of unlike charges. This
attraction makes the ions draw
together, which then releases
energy and forms the ions into a
solid “array or lattice”
Lattice Energy
• “Energy required to completely separate a
mole of a solid ionic compound into its
gaseous ions” (page 278)
• Will always be positive
• “Energy released by attraction between
ions of unlike charge makes up for the
endothermic nature of ionization
energies, making the formation of ionic
compounds”
Transition Metal-Ions
• When you form an ion, transition metals
lose the valence-shell, S electrons first,
then as many D electrons that are
required to reach the charge of the ion
Polyatomic Ions
• A group of atoms as a whole acts as a
charged species in forming an ionic
compound with an ion of the opposite
charge
Born-Haber Cycle
• Thermochemical cycle that analyzes the factors that
contribute to the stability of the ionic compounds
• Five Steps:
• 1. Generate gaseous atoms of Na by vaporizing Na
metal
• 2. Form gaseous atoms of Cl by breaking the bonds
of the Cl2 molecules
• 3 & 4: Remove the electron from Na to form Na+
and add the electron to Cl to form Cl• 5. Combine the gaseous Na and Cl ions to form solid
NaCl
Recourses
• http://ibchem.com/IB/ibfiles/bonding/bon_i
mg/NaCl4.jpg
• http://www.webelements.com/_media/elem
ents/cartoons/Na.jpg
• http://www.zingerbug.com/Backgrounds/ba
ckground_images/purple_blue_swirl.jpg