Solubility Solubility: – Amount of a solute that can dissolve in a given amount of solvent Unsaturated Solution: – Contain less than the maximum amount of solute. – Can dissolve more solute. Saturated Solution: – Contain the maximum amount of solute that can dissolve. – Have undissolved solute at the bottom of the container.

Solubility Typically, maximum number of grams of solute in 100 grams of solvent – At 20°C the solubility of KCl is 34g/100g of water. If 45g of KCl is mixed with 100g at 20°C, is the solution saturated or unsaturated? – At 50°C, the solubility of NaNO 3 is 114g/100g of water. How many grams of NaNO 3 are needed to make a saturated NaNO 3 solution with 50.g of water at 50°C.

Temperature and Solubility Generally, Solubility of solids in liquids increases as Temperature increases 3 Solubility of gases in liquids decreases as T increases

Pressure and Solubility Henry’s Law: Solubility of a gas in a liquid is directly proportional to the pressure of that gas above the liquid

Soluble and Insoluble Salts Soluble Salts: – Ionic Compounds that dissolve in water Insoluble Salts: – Ionic Compounds that remain solids when in contact with water

Solubility Rules

Formation of a Solid When salt solutions are mixed, a solid (precipitate) will form if insoluble combinations are present

Ionic and Net Ionic Equations 8 soluble insoluble Net ionic equation Ionic equation

Concentration Concentration of a solution = Mass Percent = (% m/m) Volume Percent = (% v/v) Mass/Volume Percent = (% m/v)

Practice Problem The amount of alcohol in a bottle of wine is labeled 13.5% (v/v). How much alcohol is in the entire 750. mL bottle?

Molarity Molarity (M) = What is the molarity of the solution created when you dissolve 2.5 g of NaOH in 100. mL of solution? How many grams of NaOH would you have to dissolve in water to make 100. mL of a 1.0 M solution?

Dilution Water is added to increase the volume As volume increases, concentration decreases M 1 V 1 =M 2 V 2

Molarity in Reactions How many mL of 3.00 M HCl are needed to completely react with 4.85 g CaCO 3 ? 2HCl(aq) + CaCO 3 (s) CaCl 2 (aq) + CO 2 (g) + H 2 O(l ) 4.85 g CaCO 3 x 1 mole CaCO 3 x 2 mole HCl x 1000 mL HCl g CaCO 3 1 mole CaCO mole HCl = 32.3 mL HCl required

Solutions, Colloids, and Suspensions

Colloids

Osmosis Osmosis: solvent moves from area of lower solute concentration to higher solute concentration.

Iso/Hypo/Hypertonic Solutions Isotonic: same osmotic pressure inside and out – Example: physiological solutions 0.90% (m/v) NaCl and 5.0% (m/v) glucose Hypotonic: lower osmotic pressure outside Hypertonic: higher osmotic pressure outside

Iso/Hypo/Hypertonic Solutions

Dialysis