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Chapter 8 Solutions. Colloids and Suspensions Osmosis and Dialysis. Solutions. Have small particles (ions or molecules) Are transparent Do not separate Cannot be filtered Do not scatter light. Colloids. Have medium size particles Cannot be filtered
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Chapter 8Solutions Colloids and Suspensions Osmosis and Dialysis LecturePLUS Timberlake
Solutions • Have small particles (ions or molecules) • Are transparent • Do not separate • Cannot be filtered • Do not scatter light. LecturePLUS Timberlake
Colloids • Have medium size particles • Cannot be filtered • Separated with semipermeable membranes • Scatter light (Tyndall effect) LecturePLUS Timberlake
Examples of Colloids • Fog • Whipped cream • Milk • Cheese • Blood plasma • Pearls LecturePLUS Timberlake
Suspensions • Have very large particles • Settle out • Can be filtered • Must stir to stay suspended LecturePLUS Timberlake
Examples of Suspensions • Blood platelets • Muddy water • Calamine lotion LecturePLUS Timberlake
Osmosis • In osmosis, the solvent water moves through a semipermeable membrane • Water flows from the side with the lower solute concentration into the side with the higher solute concentration • Eventually, the concentrations of the two solutions become equal. LecturePLUS Timberlake
Osmosis semipermeable membrane 4% starch 10% starch H2O LecturePLUS Timberlake
Equilibrium is reached. water flow becomes equal 7% starch 7% starch H2OO LecturePLUS Timberlake
Osmotic Pressure • Produced by the number of solute particles dissolved in a solution • Equal to the pressure that would prevent the flow of additional water into the more concentrated solution • Increases as the number of dissolved particles increase LecturePLUS Timberlake
Osmotic Pressure of the Blood • Cell walls are semipermeable membranes • The osmotic pressure of blood cells cannot change or damage occurs. • The flow of water between a red blood cell and its surrounding environment must be equal LecturePLUS Timberlake
Isotonic solutions • Exert the same osmotic pressure as red blood cells. • Medically 5% glucose and 0.9% NaCl are used their solute concentrations provide an osmotic pressure equal to that of red blood cells H2O LecturePLUS Timberlake
Hypotonic Solutions • Lower osmotic pressure than red blood cells • Lower concentration of particles than RBCs • In a hypotonic solution, water flows into the RBC • The RBC undergoes hemolysis; it swells and may burst. H2O LecturePLUS Timberlake
Hypertonic Solutions • Has higher osmotic pressure than RBC • Has a higher particle concentration • In hypertonic solutions, water flows out of the RBC • The RBC shrinks in size (crenation) H2O LecturePLUS Timberlake
Dialysis • Occurs when solvent and small solute particles pass through a semipermeable membrane • Large particles retained inside • Hemodialysis is used medically (artificial kidney) to remove waste particles such as urea from blood LecturePLUS Timberlake