Unit 12: Solutions Section 1: Properties of Solutions Solution Formation Rate of Dissolving

Can it be physically separated? Matter Flowchart MATTER yes no Can it be physically separated? MIXTURE PURE SUBSTANCE Is the composition uniform? no yes Can it be chemically decomposed? no yes Homogeneous Mixture (solution) Heterogeneous Mixture Compound Element

A. Solution Formation Solution - homogeneous mixture Solute - substance being dissolved Solvent – dissolving medium (dissolver) (present in greatest amount)

A. Solution Formation Types of Solutions: Solute Solvent Example Gas Air (O2 & CO2 in Nitrogen) Liquid Water in Air Soda Vinegar (acetic acid in water) Solid Salt in water Stainless Steel (Cr & Ni in Iron)

Why does stuff dissolve? IMAFs between solute–solute solvent–solvent must break Greater solubility: IMAFs between solute–solvent must form stronger IMAFs solute–solvent

A. Solution Formation

A. Solution Formation Electrolyte: Ionic compound that separates into ions in water to form a solution that conducts an electric current - + salt NaCl H2O NaCl (s)  Na+ (aq) + Cl- (aq)

A. Solution Formation Non-Electrolyte: Molecule whose aqueous solution does not contain ions and does not conduct an electric current. - + sugar C12H22O11

B. Rate of Dissolving Solids dissolve faster... more surface area (small particle size) 1 gram of sugar solute 1 gram of sugar solute

B. Rate of Dissolving Solids dissolve faster... more surface area (small particle size) more stirring

B. Rate of Dissolving Solids dissolve faster... more surface area (small particle size) more stirring high temp.

B. Rate of Dissolving Gases dissolve faster... no stirring high pressure low temp.

Please complete WS Solutions

Unit 12: Solutions Section 1: Properties of Solutions Solubility Factors Affecting Solubility

Solubility in 100 g of Water at 20oC C. Solubility Solubility maximum mass of solute that will dissolve in a given amount of solvent at a given temperature Solubility in 100 g of Water at 20oC Compound Solubility (g) Table Salt (NaCl) 36.0 g Baking Soda (NaHCO3) 9.6 g Table Sugar (C12H22O11) 203.9 g (0.62 mol) (0.11 mol) (0.59 mol)

Solubility Curves 1) Highest solubility at 20oC? 30oC? 2) How many grams KClO3 at 70oC ? 3) Is 50 g of KCl at 50oC sat, unsat, or supersat? 30 g of NaCl at 30oC?

less solute than max dissolved more than max solute dissolved C. Solubility UNSATURATED less solute than max dissolved SATURATED max solute dissolved SUPERSATURATED more than max solute dissolved concentration

less solute than max dissolved more than max solute dissolved C. Solubility UNSATURATED less solute than max dissolved SATURATED max solute dissolved SUPERSATURATED more than max solute dissolved Add a seed crystal concentration

less solute than max dissolved more than max solute dissolved C. Solubility UNSATURATED less solute than max dissolved SATURATED max solute dissolved SUPERSATURATED more than max solute dissolved concentration

less solute than max dissolved more than max solute dissolved C. Solubility UNSATURATED less solute than max dissolved SATURATED max solute dissolved SUPERSATURATED more than max solute dissolved Extra solute crystallizes concentration

D. 3 Factors Affecting Solubility Temp. Pressure high T: solids more soluble low T: gases more soluble high P: gases more soluble

similar IMAFs dissolve D. Factors Affecting Solubility Polarity: “Like Dissolves Like” similar IMAFs dissolve H H H C C C H C C C C6H14 H H H H2O CCl4

D. 3 Factors Affecting Solubility Polar –Polar Polar –Nonpolar

Quick Quiz. 1) For a given substance, which of the following will NOT influence how fast it dissolves? A) temperature B) amount of agitation C) molar mass D) size of the crystals

Quick Quiz. 3) The solubility of a gas in a solvent is affected by? A) both temperature and pressure. B) only pressure C) only temperature D) your face

Quick Quiz. 4) Polar water molecules will NOT dissolve… A) polar alcohol molecules B) most ionic compounds C) nonpolar fat molecules D) partially ionized acetic acid molecules