CH 301 Chapter 5 notes part1v2

CH 301 Chapter 5 notes part1v2 - Chapter 5: Liquids and...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 5: Liquids and Solids: CONDENSED phases of matter. Van der Waal’s equation: gas particles have size and some attractive force. High P, Low T: particles close enough - attractive effects become significant gas condenses to liquid (or deposits to solid) further cooling of liquid - freezes to solid. Attractive forces between particles: due to COULOMBIC attraction between: positive particle charge q+ q + q - r negative particle charge q- separated by a distance r: Coulomb’s Law: F (q+ )(q- ) r 2 Energy = Force x Distance so Potential Energy of Attraction E p = (q+ )(q- ) 4 Πε 0 r Types of Forces INTRAmolecular force: covalent bonding between individual atoms in molecule or polyatomic ion. e.g., bond between: C and O in CO 2 S and O in SO 4 2- INTRAionic force: ionic bonding between individual ions in lattice of a crystal e.g., bond between: Mg 2+ and Cl - in MgCl 2 Mg 2+ and SO 4 2- in MgSO 4 INTERmolecular forces: several types (see following. .) between individual atoms, ions or molecules of a compound or mixture. e.g., forces between: separate CO 2 molecules in CO 2 H 2 O molecules and dissolved Na + , Cl - ions Warning! If you don’t remember how to tell if a compound is covalent, polar covalent or ionic: GO BACK AND REVIEW CHAPTERS 2-3 REMEMBER: A molecule which is polar overall will have a NET DIPOLE. From now on we refer to this as a DIPOLE. Ion-Dipole Interaction Aqueous solutions of ionic compounds consist of ions with attached water molecules. O H H δ δ δ + HYDRATION: water molecules surround and bond to ions Water is a POLAR molecule - has a net DIPOLE:Each H 2 O molecule orients itself: O side is negatively charged ( δ -) so is closest to a positive ion, for a negative ion, side with H’s ( δ +) would be closest Potential Energy of an Ion-Dipole Attraction: Ep - z μ NOTE: a 1/r 2 dependence r 2 z = charge on the ion, μ = dipole moment of the polar molecule (e.g. water in this image) red is negative, blue positive. Which is the anion, cation? Ion – Dipole interactions are WEAKER than ion-ion attractions.
Background image of page 1

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

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 4

CH 301 Chapter 5 notes part1v2 - Chapter 5: Liquids and...

This preview shows document pages 1 - 2. Sign up to view the full document.

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