CHAPTER 7 CONCURRENT ENROLLMENT

SOLUTIONS Solutions A homogenous mixture of two or more substances in which the components are atoms, molecules or ions. Solute A substance (usually are solid or gas) that dissolves into a solvent. Solvent What causes the solute to dissolve.

CONTINUED Dissolving 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 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 Like dissolves like Polar solvents will dissolve polar or ionic compounds Polar solvents will dissolve polar or ionic compounds Nonpolar solvents will dissolve nonpolar compounds Nonpolar solvents will dissolve nonpolar compounds

SOLUBILITY Soluble Soluble A solute that dissolves into a solvent to a large extent A solute that dissolves into a solvent to a large extent Insoluble Insoluble A solute that does not dissolve very much into a solvent A solute that does not dissolve very much into a solvent Immiscible Immiscible A term used to describe liquids that are insoluble in each other A term used to describe liquids that are insoluble in each other Solubility Solubility Maximum amount of solute that can be dissolved in a specific amount of solvent under specific conditions of temperature and pressure Maximum amount of solute that can be dissolved in a specific amount of solvent under specific conditions of temperature and pressure

CONTINUED Saturation solution Saturation solution Maximum amount possible of dissolved solute in a stable situation at a certain temperature and pressure Maximum amount possible of dissolved solute in a stable situation at a certain temperature and pressure Supersaturated solution Supersaturated solution Unstable solution that contains an amount of solute greater than the solute solubility at a certain temperature and pressure Unstable solution that contains an amount of solute greater than the solute solubility at a certain temperature and pressure

SOLUTION PROCESS Ionic solids are held together by charge attraction. The attraction to the water molecule is greater than between the ions so they dissociates 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 Hydrated ion Ion surrounded by water molecules Ion surrounded by water molecules A solute will not dissolve in a solvent if 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 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 The solvent particles are more strongly attracted to each other

CONTINUED Ionic compounds will dissolve in water following the rules found on page 212. Ionic compounds will dissolve in water following the rules found on page 212. Ways to increase the dissolving rate Ways to increase the dissolving rate Crush or grind the solute Crush or grind the solute Heat the solvent Heat the solvent Stirring Stirring

MOLARITY Concentration Amount of solute contained in a specific amount of solution Molarity Number of moles of solute contained in a liter of solution M (molarity) = moles of solute liters of solution Percent concentration Solution concentration that expresses the amount of solute in 100 parts of solution % = part X 100 total

CONTINUED Weight/weight percent Concentration that expresses the mass of solute contained in 100 mass units of solution %(w/w) = solute mass X 100 solution mass

PROBLEMS Weight/volume percent Concentration that expresses the grams of solute contained in 100 mL of solution %(w/v) = grams of solute X 100 milliliters of solution Volume/volume percent Concentration that expresses the volume of liquid solute contained in 100 volumes of solution %(v/v) = solute volume X 100 solution volume

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

PROPERTIES Electrolyte Electrolyte A Solute that when it dissolves forms many ions that allow it to conduct electricity A Solute that when it dissolves forms many ions that allow it to conduct electricity Nonelectrolyte Nonelectrolyte A solute that when dissolved does not form ions and will not conduct electricity A solute that when dissolved does not form ions and will not conduct electricity

CONTINUED Colligative properties Colligative properties Solution property that depends on the concentration of solute particles in solution Solution property that depends on the concentration of solute particles in solution Δt b = nK b M Δt b = nK b M Δt f = nK f M Δt f = nK f M K = constant, will be given, M = molarity, Δt = change in temperature 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 The process in which solvent flows through a semipermeable membrane into a solution Osmolarity π = nMRT; n = moles, M = molarity, R = constant, T = temperature

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 - Dispersed phase - Solute particles found in solutions do not scatter light, whereas dispersed phase particles in colloids do. This is called the Tyndall Effect Emulsifying agent A substance that when added to colloids prevents then from coalescing and setting

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 hemolysis

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 does not change to cause hemolysis or crenation Hypertonic Solution with higher osmolarity Hypotonic Solution with lower osmolarity