Increasing the concentration of solute particles in the solution Decreases the

Increasing the concentration of solute particles in

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Increasing the concentration of solute particles in the solution: Decreases the number of solvent particles at the surface of the solution Prevents some of the solvent particles from leaving the solution Boiling Point Elevation Increasing the concentration of nonvolatile solute particles in the solution raises the boiling point of the solution, and: More solute particles in the solution lowers the vapor pressure The solution boils at a higher temperature than the normal boiling point Freezing Point Lowering Adding salt to an icy road when temperatures drop below freezing:
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Allows the particles of salt to mix with the water Lowers the freezing point of the ice Particles in Solution A solute that is a nonelectrolyte dissolves as molecules, whereas a solute that is a strong electrolyte dissolves entirely as ions The solute in antifreeze, which is ethylene glycol, C 2 H 6 O 2 , is a nonelectrolyte and dissolves as molecules in water 1 mole C 2 H 6 O 2 (l) = 1 mole C 2 H 6 O 2 (aq) The solute NaCl, a strong electrolyte, dissolves as ions in water NaCl (s) = 1 mole Na + (aq) + a mole Cl - (aq) 1 mole NaCl (s) = 2 moles of particles in solution Osmosis In osmosis: Water (solvent) flows from a lower to a higher solute concentration The level of the solution with the higher solute concentration rises The concentrations of the two solutions become equal over time Osmotic pressure is: Equal to the pressure that would prevent the flow of additional water into the more concentrated solution Greater as the number of dissolved particles in the solution increases
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Reverse Osmosis In a process called reverse osmosis a pressure greater than the osmotic pressure is applied to a solution, forcing it through a purification membrane The flow of water is reversed because water flows from an area of lower to higher water concentration, leaving behind the molecules and ions in solution Isotonic Solutions Because cell membranes in biological systems are semipermeable, osmosis is an ongoing process The solutes in body solutions such as blood, tissue fluids, lymph, and plasma all exert osmotic pressure Most IV solutions used in hospitals are isotonic solutions, which: Exert the same osmotic pressure as body fluids such as red blood cells (RBCs) Include a 5.0% (m/v) glucose or 0.90% (m/v) NaCl isotonic solution Hypotonic and Hypertonic Solutions If a red blood cell is placed in a solution that is not isotonic, the differences in osmotic pressure inside and outside the cell can alter the volume of the cell A hypotonic solution : Has a lower solute concentration than red blood cells Means water flows into cells by osmosis The increase in fluid causes the cells to swell and burst, a condition known as hemolysis A hypertonic solution : Has a higher solute concentration than RBCs Involves water going out of the cells by osmosis Causes crenation - RBCs shrink in size
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Dialysis In dialysis:
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