Chapter_11_Part2_S22_S61

Chapter_11_Part2_S22_S61 - 11.4 Intermolecular Forces in...

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
A. Viscosity Substances with large imf (more “sticky”) are more c they flow Compare gasoline, , and tar c all hydrocarbons – Dispersion Forces t Viscosity usually drops with c molecules have more KE to overcome the imf 11.4 Intermolecular Forces in Action B. Surface Tension Surface molecules are – they have imf with molecules only on . Droplets are spherical to minimize the number of high energy c Larger imf – larger surface tension
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Surface Tension C. Capillary Action -Meniscus
Background image of page 2
Adhesive and Cohesive Forces Liquid on a surface has a balance of cohesive imf between the molecules and adhesive forces between the molecules and the surface Water on glass – adhesive forces to silica are than imf in water – get a meniscus Capillary action – in a small tube the attraction to the walls causes a Mercury on glass – metal-metal forces are very large – get a meniscus Water on waxed cars-? Tro, Chemistry: A Molecular Approach 27 A Clicker Question
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
11.5 Vaporization and Vapor Pressure Volatility – tendency of a liquid to at a given temperature (usually 25ºC) Weak imf = A volatile liquid open to the atmosphere will vaporize, most molecules will escape, Fraction with KE above the threshold grows exponentially A. The Process of Vaporization 1. Heat of Vaporization As only the highest energy molecules escape the liquid, the of the remainder drops The remaining liquid – vaporization is endothermic H 2 O (l) H 2 O (g) H vap = +40.7 kJ/mol @100°C Condensation is – heat is released to the surroundings H 2 O (g) H 2 O (l) H = -40.7 kJ/mol @100°C B. The Energetics of Vaporization
Background image of page 4
2. Vaporization of water How much heat is needed to vaporize 5.00g of H 2 O(l) @100°C? 2 2 2 2 1mol H O 40.7kJ 5.00g H O 18.0g H O 1molH O × × = 3. Molar Enthalpies of Vaporization imf
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
C. Vapor Pressure and Dynamic Equilibrium Initially no vapor, molecules until the vapor pressure is high enough that of molecules
Background image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/01/2010 for the course CHEM 12412 taught by Professor Af during the Summer '10 term at CSU Long Beach.

Page1 / 20

Chapter_11_Part2_S22_S61 - 11.4 Intermolecular Forces in...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online