AP Chemistry/Solutions

Molarity versus Molality

 * Molarity (M) - moles of solute per liter of solution.
 * Molality (m) - moles of solute per kilogram of solvent.

Solubility Rules
These will NOT be given to you on the test. You must memorize them.
 * 1) Compounds with Group 1 elements are soluble or the ammonium ion are soluble.
 * 2) Nitrates, acetates, chlorates, and perchlorates are soluble.
 * 3) Chlorides, bromides, and iodides are generally soluble, unless they contain copper, silver, lead, or mercury.
 * 4) Sulfates are soluble, unless they contain barium, lead, silver, strontium, or calcium.
 * 5) Most silver salts are insoluble unless listed in rule #2.
 * 6) Most hydroxide salts are insoluble unless stated in rule #1 or contain calcium, strontium, or barium.
 * 7) Most sulfides are insoluble unless stated in rule #1, or contain Group 2 elements.
 * 8) Carbonates and phosphates are insoluble unless listed in rule #1.

Forgot Your Polyatomic Ions?

 * Ammonium -
 * Nitrate -
 * Acetate -
 * Chlorate -
 * Perchlorate -
 * Sulfate -
 * Carbonate -
 * Phosphate -

Solubility

 * Solids are more soluble when they are warm, but gases are the opposite.
 * Supersaturated solutions will settle if disturbed.

Colligative Properties
Colligative properties are properties of solutions that depend on the amount of solute particles present rather than the identity of the particles.
 * Vapor pressure lowering
 * Freezing point depression and boiling point elevation (molality)
 * Osmotic pressure

Not Solutions

 * Colloids look "milky" when light is passed through them (Tyndall Effect)
 * Suspensions settle if left long enough, and also look milky.