BTEC1322 1st Edition Lecture 5 Outline of Last Lecture - Vapor pressure- Boiling point- Freezing point- Determination of massOutline of Current Lecture - Osmotic pressure- Endothermic and Exothermic outcomes- SolubilityCurrent Lecture- Nonvolatile, non-electrolyte solute is a liquid solvent a colligative property is osmotic pressure- In this case there is a semi-permeable membrane between a pure solvent and a solution - There are holes in the membrane where the solvent molecules can pass but they are to small for the solute molecules to cross- In this u-tube the solvent particles pass through the membrane These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- As this happens one side goes down and the other goes up- There are two opposing factors the osmosis where the water wants to go to the right and gravity where the water does not want to go to the right- Osmotic pressure really is the pressure needed to stop osmosis - The formula is osmotic pressure= MRT- M is the molar mass R is a constant and T is temperature- This formula can be used as for molar mass determination- Ionic dissociation in water leads to more sizeable changes- Ex. 0.1 m of ethanol has a change is freezing point of -.2 Celsius but 0.1 m of NaCl is different it has a change of -.4 Celsius which is twice the difference and this is because Na and Cl spit in water- Solute particles then get in the way- In a solvent and solute the intermolecular forces (imf) break but in a solution new imfs are created- The breaking of imfs in endothermic while the making is exothermic- In a exothermic reaction it is nice because a solute is soluble in a solution - In this case the imfs of a solution are greater than the solute and solvent- In a reaction that is a little endothermic the solute is still soluble - The imfs in the solute and solvent are about equal to the solution- In a reaction that is very endothermic it is nasty and the solute is insoluble in the solvent- In this reaction the imfs in the solution are less than the solute and solvent- Like dissolves like which means that that similar intermolecular forces for example a dipole-dipole solute dissolves in a dipole- dipole solvent- Unlike does not dissolve unlike meaning that different imfs between the solute and solvent makes the solute insoluble for example and ionic solute will not dissolve in a nonpolar solvent - Kinda like might dissolve in kinda like for example a hydrogen bond solute will dissolve ina ionic solventKey TermsOsmotic Pressure- the amount of pressure provided to prevent solvent from crossing the membraneIonic dissociation- Ionic compounds split into
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