Solutions  Definitions  Types of Solution  Solutions, Colloids, Suspensions  Process of Dissolving  Rate of Solution  Concentration  Solubility

Definitions  Homogenous Mixture – two or more substances which have the same composition throughout; uniform; in the same state of matter Solutions, Colloids, Suspensions  Heterogeneous Mixture – two or more substances which have a mixture in which the ingredients are not uniformly dispersed. Fruity Pebbles

Definitions  Solution -  Solution - homogeneous mixture of two or more substances Solvent Solvent - present in greater amount Solute Solute - substance being dissolved, present in smaller amount Solute particles very small

Definitions Solute Solute - KMnO 4 Solvent Solvent - H 2 O

Hydrogen Bonds Attract Polar Water Molecules

Types of Solutions  Based on state of solvent.  All solid-liquid-gas combos are possible.  EX: dental amalgam (alloy of silver, mercury, etc.) liquid solute, solid solvent solid solution

Types of Solutions air O 2 gas and N 2 gas gas/gas soda CO 2 gas in water gas/liquid seawater NaCl in water solid/liquid brass copper and zinc solid/solid

Learning Check SF1 (1) element (2) compound (3) solution A. water123 B. sugar 123 C. salt water 123 D. air123 E. tea123

Solution SF1 (1) element (2) compound (3) solution A. water2 B. sugar 2 C. salt water 3 D. air3 E. tea3

Learning Check SF2 Identify the solute and the solvent. A. brass: 20 g zinc + 50 g copper solute= 1) zinc 2) copper solvent = 1) zinc 2) copper B. 100 g H 2 O + 5 g KCl solute = 1) KCl 2) H 2 O solvent = 1) KCl 2) H 2 O

Solution SF2 A. brass: 20 g zinc + 50 g copper solute= 1) zinc solvent = 2) copper B. 100 g H 2 O + 5 g KCl solute = 1) KCl solvent = 2) H 2 O

Dissolving  Solvation occurs at the surface of the solute solvent particles surround solute particles (+/- attraction) solute particles are pulled into solution

Dissolving NaCl dissolving in water

“Like Dissolves Like” NONPOLAR POLAR  Detergents polar “head” with long nonpolar “tail” can dissolve both types

Learning Check SF4 Which of the following solutes will dissolve in water? Why? 1) Na 2 SO 4 2) gasoline 3) I 2 4) HCl

Like dissolves like A ____________ solvent such as water is needed to dissolve polar solutes such as sugar and ionic solutes such as NaCl. A ___________solvent such as hexane (C 6 H 14 ) is needed to dissolve nonpolar solutes such as oil or grease.

Solution SF4 Which of the following solutes will dissolve in water? Why? 1) Na 2 SO 4 Yes, polar (ionic) 2) gasoline No, nonnpolar 3) I 2 No, nonpolar 4) HClYes, Polar

Colloids Have medium size particles Cannot be filtered Separated with semipermeable membranes Scatter light (Tyndall effect)

Examples of Colloids Fog Whipped cream Milk Cheese Blood plasma Pearls

Suspensions Have very large particles Settle out Can be filtered Must stir to stay suspended

Examples of Suspensions Blood platelets Muddy water

Rate of Solution - Solids  Solids dissolve faster (have greater solubility) with... more stirring small particle size (increased surface area) high temperature

Temperature and Solubility of Solids TemperatureSolubility (g/100 g H 2 O) KCl(s)NaNO 3 (s) 0° °C °C °C The solubility of most solids (decreases or increases ) with an increase in the temperature.

Temperature and Solubility of Solids TemperatureSolubility (g/100 g H 2 O) KCl(s)NaNO 3 (s) 0° °C °C °C The solubility of most solids increases with an increase in the temperature.

Rate of Solution - Gases  Gases dissolve faster and have great solubility if... no shaking or stirring high pressure above surface low temperature

Temperature and Solubility of Gases TemperatureSolubility(g/100 g H 2 O) CO 2 (g)O 2 (g) 0°C °C °C The solubility of gases (decreases or increases) with an increase in temperature.

Temperature and Solubility of Gases TemperatureSolubility(g/100 g H 2 O) CO 2 (g)O 2 (g) 0°C °C °C The solubility of gases decreases with an increase in temperature.

Concentration  Concentrated solution large amount of solute  Dilute solution small amount of solute

Concentration  % by Volume  % by Volume: usu. liquid in liquid EX: 10% juice = 10mL juice + 90mL water  % by Mass  % by Mass: usu. solid in liquid EX: 20% NaCl = 20g NaCl + 80g water % solution = mass of solute x 100 mass of solution

Concentration SATURATED SOLUTION no more solute dissolves UNSATURATED SOLUTION more solute dissolves SUPERSATURATED SOLUTION becomes unstable, crystals form concentration

Solubility  Solubility maximum grams of solute that will dissolve in 100 g of solvent at a given temperature varies with temperature based on a saturated solution g of solute 100 g water

Learning Check S1 At 40  C, the solubility of KBr is 80 g/100 g H 2 O. Indicate if the following solutions are (1) saturated or (2) unsaturated A. ___60 g KBr in 100 g of water at 40  C B. ___200 g KBr in 200 g of water at 40  C C. ___25 KBr in 50 g of water at 40  C

Solution S1 At 40  C, the solubility of KBr is 80 g/100 g H 2 O. Indicate if the following solutions are (1) saturated or (2) unsaturated A. 2 Less than 80 g/100 g H 2 O B. 1 Same as 100 g KBr in 100 g of water at 40  C, which is greater than its solubility C. 2 Same as 60 g KBr in 100 g of water, which is less than its solubility