Ionic compounds generally are a non-metal with a metal

e- spend more time around the more electronegative (polyatomic) ion

disproportional sharing of electrons causes a (+ve) charged ion & (-ve) charge ion

The (+ve) & (-ve) ions form a lattice (a solid structure)

Sodium ion

Water molecule Chlorine ion

Q: What happens when this gets into water (a polar substance with + and -)?

A: The ions are pulled off by the water, with opposite charges attracting

Sodium ion

Water molecule

Chlorine ion

http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/molvie1.swf

NaCl (solid) + H2O (liquid) NaCl (aqueous)

Is there a simpler method to write this? Use symbols

NaCl(s) NaCl(aq) Molecular Equation

OR

NaCl(s) Na+(aq) + Cl- (aq) Ionic Equation

H2O

H2O

What Occurs if we mix a solution of◦ Sodium Chloride

AND◦ Silver Nitrate

What do we observe?◦ The white substance means that a ionic solid has

formed that is not dissolved in the water◦ What is the formula of this solid?

What are the two possibilities?

(NaCl)

(AgNO3)

Molecular Equation: NaCl(aq) + AgNO3(aq) AgCl(s) + NaNO3(aq)

Ionic Equation: Na+

(aq) + Cl-(aq) + Ag+(aq) + NO3

-(aq) → AgCl(s) + Na+

(aq) + NO3-(aq)

◦ What ions exist on both sides of the equation?

◦ These can be cancelled out (Known as spectator ions)

Net Ionic Equation: Cl-(aq) + Ag+

(aq) → AgCl(s)Note: Remember your charges need to be balanced on both sides of the equation!

Why would this solid not dissolve in the water when the ions before were dissolved?

The force of attraction between the two ions (Ag+ & Cl- ions) are stronger than the force of attraction between the ions and the polar water molecule

http://www.crescent.edu.sg/crezlab/webpages/pptreaction4.htm