CONCURRENT ENROLLMENT CHAPTER 7 CONCURRENT ENROLLMENT

SOLUTIONS Solutions Made up of a solute and solvent Solute Less amount than solvent Solvent Largest amount in a solution

CONTINUED Dissolving A term used to describe the process of solution formation when one or more solutes are dispersed in a solvent to form a homogeneous mixture Like dissolves like Polar solvents will dissolve Nonpolar solvents will dissolve

SOLUBILITY Soluble - A substance that dissolves in a solvent Insoluble - A substance that does not dissolve in a solvent Two liquids that can be mixed but separate shortly after are immiscible. Oil and water Solubility Maximum amount of solute that can be dissolved in a specific amount of solvent under specific conditions of temperature and pressure (overhead)

CONTINUED Unsaturated solutions are solutions that contain less dissolved solute for a given temperature and pressure than a saturated solution. Saturated solutions contain the maximum amount of dissolved solute for a given amount of solute at a specific temperature and pressure. A supersaturated solution contains more dissolved solute than a saturated solution at the same temperature To form a supersaturated solution, a saturated solution is formed at high temperature and then slowly cooled. Supersaturated solutions are unstable Demo

SOLUTION PROCESS Learning check page 209 Ionic solids are held together by charge attraction. The attraction to the water molecule is greater than between the ions so they dissociates Hydrated ion A solute will not dissolve in a solvent if The forces between solute particles are too strong to be overcome by interactions with the solvent particle The solvent particles are more strongly attracted to each other

CONTINUED Ionic compounds will dissolve in water following the rules found on page 212. Memorize Ways to increase the dissolving rate Crush or grind the solute (smaller particles have more surface area) Heat the solvent (solvent molecules are moving faster) Stirring (places unsaturated solvent by the solute particles)

The concentration of a solution is a measure of how much solute is dissolved in a specific amount of solvent or solution Concentration can be described as concentrated or dilute.

MOLARITY Concentration Molarity M (molarity) = moles of solute liters of solution Learning check page 215 Percent concentration % = part X 100 total Weight/weight percent %(w/w) = solute mass X 100 solution mass

PROBLEMS Weight/volume percent Volume/volume percent %(w/v) = grams of solute X 100 milliliters of solution Volume/volume percent %(v/v) = solute volume X 100 solution volume

CONTINUED M1V1 = M2V2 or C1V1 = C2V2 C = M, %(v/v), or %(w/v)

PROPERTIES Figure 7.10 page 221 Learning check page 223 Electrolyte Ionic compounds are electrolytes because they dissociate in water to form a solution that conducts electricity. Electrolytes that produce many ions are strong electrolytes. Electrolytes that produce only a few ions are weak electrolytes Nonelectrolyte Many molecular compounds do not ionize when dissolved, and do not conduct electricity, these are called nonelectrolytes. There are some exceptions, so those molecular compounds that do ionize are electrolytes

CONTINUED Colligative properties are physical properties of solutions that are affected by the number of particles but not by the identity of dissolved solute particles. Colligative means depending on the collection Colligative properties include: vapor pressure lowering, boiling point elevation, freezing point depression and osmotic pressure. Δtf = nKfM K = constant, will be given, M = molarity, Δt = change in temperature

OSMOTIC PRESSURE Hydrostatic pressure required to prevent the net flow of solvent through a semipermeable membrane into a solution Osmosis is the diffusion of a solvent through a semipermeable membrane

Osmolarity Demo Learning check page 230 π = nMRT; n = moles, M = molarity, R = constant, T = temperature Demo Learning check page 230

COLLOIDS Homogeneous mixture of two or more substances in which the dispersed substances are present as larger particles than are found in solution Dispersing medium - is the solvent Dispersed phase - is the solute Solute particles found in solutions do not scatter light, whereas dispersed phase particles in colloids do. This is called the Tyndall effect Emulsifying agent Mayonnaise is a colloid of oil in water, with egg yolk acting as the emulsifying agent

DIALYSIS AND RED BLOOD CELLS A process in which solvent molecules, small molecules and hydrated ions pass from a solution through a membrane Dialyzing membrane A semipermeable membrane with pores large enough to allow Solvent molecules, small molecules and hydrated ions to pass through When RBC cells are placed in distilled water it causes the water to flow into the cell to lower the concentration level When this occurs it causes the cell to burst this is called

CONTINUED When the concentration of the fluid outside of the cell is higher it causes the water to flow out of the cell When this occurs it causes the cell to shrink this is called Crenation Intravenous drips must be made correctly so that the osmolarity Hypertonic higher concentration of solutes outside the cell than inside the cell Hypotonic higher concentration of solutes inside the cell than outside the cell