1. Chapter 13-1 Types of Mixtures

2. solutions  Soluble: capable of being dissolved  Solution: a homogenous mixture of two or more substances in a single phase  Solvent: the dissolving medium  Solute: the substance being dissolved Usually 0.01 to 1 nm Usually 0.01 to 1 nm Cannot be filtered out Cannot be filtered out

3. suspensions  When particles in a solvent are so large that they settle out when left alone it is called a suspension Particles sizes are usually over 1,000 nm Particles sizes are usually over 1,000 nm Can be filtered out Can be filtered out Ex: muddy waterEx: muddy water

4. colloids  Particles that are intermediate in size between those in solutions and suspensions from mixtures known as colloidal dispersions, or Colloids Particle size between 1 and 1,000 nm Particle size between 1 and 1,000 nm Particles pass through filter Particles pass through filter Cloudy portion of muddy waterCloudy portion of muddy water SmokeSmoke MayonnaiseMayonnaise Fog (tyndall effect)Fog (tyndall effect)

5. Solutes  Electrolyte: a substance that dissolves in water to give a solution that conducts electric current NaCl, HCl, other highly polar compounds that ions separate out when dissolved in water NaCl, HCl, other highly polar compounds that ions separate out when dissolved in water  Nonelectrolytes: a substance that dissolved in water to give a solution that does not conduct an electric current sugar sugar

6. Chapter 13-2  The Solution Process

7. Rate of Dissolution  Increased surface area (crushing) speeds up dissolution  Agitation: stirring brings undesolved particles to areas that have not been saturated yet, thereby increasing speed  Temperature: heat increases particle motion thereby increasing speed of dissolution

8. Solubility  Solution equilibrium: dissolution = crystallization of solute  Point of equilibrium depends on nature of solute, the nature of solvent and the temperature.  Saturated: a solution that contains the maximum amount of dissolved solute

9. Saturation continued  Unsaturated: contains less solute than saturated solution  Supersaturated: a solution that contains more dissolved solute than a saturated solution contains under the same conditions  Solubility: amount of substance needed to form a saturated solution with specific amount of solvent at specific temperature

10. Solute-Solvent Interactions  “Like dissolves Like”  Hydration: a solution process with water as the solvent Ionic compounds dissociate to bond with polar ends of water molecules Ionic compounds dissociate to bond with polar ends of water molecules

11. Nonpolar Solvents  Ionic compounds generally do NOT dissolve into nonpolar solvents

12. Liquid Solutes and Solvents  Immiscible: liquid solutes and solvents that are NOT soluble in each other Oil and water Oil and water  Miscible: liquids that dissolve freely in one another in any proportion

13. Effects of Pressure on Solubility  Pressure has very little affect on solubility of solids and liquids  Increasing pressure increases gas solubility in liquids

14. Henry’s Law  The solubility of a gas in a liquid is directly proportional to the partial pressure of that gas on the surface of the liquid  Effervescence: the rapid escape of a gas from a liquid in which it is dissolved CO2 in soda (bottled at 5-10 atm) CO2 in soda (bottled at 5-10 atm)

15. Effects of Temp on Solubility  Gas solubility in liquids decreases with increasing temperature  Solids are hard to predict, but generally increase in solubility with increasing temps (some solids increase greatly, some only a little and some actually decrease)

16. Heats of Solution  Solvated: when a solute particle is surrounded by solvent molecules  Heat of solution: the amount of heat energy absorbed or released when a specific amount of solute dissolves in a solvent + = endothermic (absorbing heat) + = endothermic (absorbing heat) - = exothermic (gives off heat) - = exothermic (gives off heat) (gaseous solutes are always exothermic) (gaseous solutes are always exothermic)

17. 13-3 Concentration of Solutions  Concentration: the measure of the amount of solute in a given amount of solvent or solution  Molarity: the number of moles in 1 liter of solution (mol/L expressed as M)

18. Molarity practice problems  1. what is the molarity of a 3.50 L solution that contains 90.0g of sodium chloride?  1. ANS0.440M  2. How many moles of HCl are contained in an 0.8 L container of 0.5M of solution  2. ANS0.4 mol  3. What volume (in mL) of solution is needed to give you 23.4 g of potassium chromate out of a 6.0M solution?  3. ANS20.mL

19. Molality  The concentration of a solution in Moles per Kg of solvent (expressed as m)

20. Practice Molality problems  1. 17.1 g of sucrose (C 12 H 22 O 11 ) in 125g of water has what molality?  1. ANS0.400m  How many grams of Iodine (I 2 ) is needed to prepare 0.480m solution in 100g of CCl 4 ?  2. ANS12.2g  What is the molality of a solution with 255g of acetone, (CH 3 ) 2 CO in 200.g of water?  3. ANS22.0m

21. Parts per notation  /hundred (% solution) Calculation is g/100mL of water Calculation is g/100mL of water  /million (ppm) 1mg/L of water  What we will use 1mg/L of water  What we will use Or mg/kg of soil Or mg/kg of soil  /billion (ppb)  g/L of water  what we will use  g/L of water  what we will use Or  g/kg of soil Or  g/kg of soil