Colligative Properties Depend on the concentration of solute particles, but not on chemical...
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- Slide 1
- Colligative Properties Depend on the concentration of solute
particles, but not on chemical identity. In the case of a solute
that does not ionize, concentration of solute particles has the
same meaning as solute concentration.
- Slide 2
- Some Colligative Properties Vapor pressure lowering Boiling
point elevation Freezing point depression Osmotic pressure
- Slide 3
- Why Vapor Pressure Lowering? Results when a non-volatile solute
is dissolved in a volatile solvent. Only some of the surface
molecules have the ability to vaporize, compared to all of the
surface molecules in the case of a pure solvent. As a result, the
vapor pressure of the solution is less than that of a pure
solvent.
- Slide 4
- Molecular-Level Explanation for Vapor Pressure Lowering (image
1 of 3)
- Slide 5
- Molecular-Level Explanation for Vapor Pressure Lowering (image
2 of 3)
- Slide 6
- Molecular-Level Explanation for Vapor Pressure Lowering (image
3 of 3)
- Slide 7
- An Interesting Illustration of the Difference in Vapor Pressure
Between Solvent and Solution
- Slide 8
- Raoults Law P = X. P o Obeyed exactly, only for ideal solutions
For non-ideal solutions, Raoults law is more closely followed for
dilute solutions
- Slide 9
- Slide 10
- Raoults Law Applied to Both Solvent and Solute (when both are
volatile) P = X. P o P = P + P = X. P o + X. P o = (1-X). P o + X.
P o
- Slide 11
- Slide 12
- Vapor Pressure Lowering Changes the Boiling and Freezing
Points
- Slide 13
- Equations for Boiling Point Elevation and Freezing Point
Depression T b = T b T o b and T b = K b. c m T f = T f T o f and T
f = -K f. c m
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