Solutions Continued Brownian Motion- The constant random motion of particles in colloids such as smoke. Tyndall Effect-Scattering of light by colloid particles.

Electrolytes Pure water does NOT conduct electricity very well. If a substance releases ions (atoms with a positive or negative charge) in water, the water will then conduct electricity. Any substance which produces ions in water is called an electrolyte.

Strong Electrolytes Strong electrolytes ionize completely (100%) in water, allowing the solution to conduct electricity very well. There are basically 3 classes of strong electrolytes: 1) soluble salts (AKA ionic compounds) 2) strong acids 3) strong bases

Aqueous Solutions How do we know ions are present in aqueous solutions? The solutions conduct electricity! They are called ELECTROLYTES HCl, MgCl2, and NaCl are strong electrolytes. They dissociate completely (or nearly so) into ions.

When ionic compounds dissolve in water, they ionize: Ionic compound  cation(s) + anion(s) MgCl2 (s)  NaOH (s)  NH4OH (s)  NaNO3 (s)  HNO3 (l)  C6H12O6 (s)  K3PO4 (s)  Na2SO4 (s)  C12H22O11(s) 

NaCl HCl HC2H3O2 C3H7OH

Weak electrolytes Weak electrolytes are substances which only a small percentage of particles form ions in water. So, they conduct electricity poorly in water.

Nonelectrolytes: Some molecules dissolve in water, because they are polar(uneven distribution of charge), just like water. They do not form ions because they are covalent(molecular) molecules, not cation/anion pairs. Sugars (CxHyOz) are examples of nonelectrolyte , solids. (molecular, covalent) In Summary, there are two types of solutes: 1 ) Ionic(Electrolytes) 2) Covalent(Nonelectrolytes, Molecular)

How to prepare a solution Demonstrate with CuSO4

Solutions part II Unsaturated, Sat., Supersat. Solution on board

Quiz tomorrow!

Solubility of Ionic Compounds

Concentration of Solutions