Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around...
-
date post
19-Dec-2015 -
Category
Documents
-
view
218 -
download
1
Transcript of Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around...
![Page 1: Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around central atom. Axial atomsEquatorial atoms.](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649d3a5503460f94a1538b/html5/thumbnails/1.jpg)
Lecture 31 11/18/05
![Page 2: Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around central atom. Axial atomsEquatorial atoms.](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649d3a5503460f94a1538b/html5/thumbnails/2.jpg)
Electron Pair Geometries
Molecules with only single covalent bonds around central atom.
Axial atoms Equatorial atoms
![Page 3: Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around central atom. Axial atomsEquatorial atoms.](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649d3a5503460f94a1538b/html5/thumbnails/3.jpg)
Repulsion
Lone pair – Lone pair
Lone pair – Bonding pair
Bonding pair – Bonding pair
Highest repulsion
![Page 4: Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around central atom. Axial atomsEquatorial atoms.](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649d3a5503460f94a1538b/html5/thumbnails/4.jpg)
Geometries for Four Electron Pairs
![Page 5: Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around central atom. Axial atomsEquatorial atoms.](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649d3a5503460f94a1538b/html5/thumbnails/5.jpg)
Molecular Geometries for Five Electron Pairs
![Page 6: Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around central atom. Axial atomsEquatorial atoms.](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649d3a5503460f94a1538b/html5/thumbnails/6.jpg)
Molecular Geometries for Six Electron Pairs
![Page 7: Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around central atom. Axial atomsEquatorial atoms.](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649d3a5503460f94a1538b/html5/thumbnails/7.jpg)
Example: What is the geometry of NH3?
1. Draw Lewis structure2. Determine # of bonds and lone pairs around central atom3. Electron-pair geometry4. Molecular geometry
![Page 8: Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around central atom. Axial atomsEquatorial atoms.](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649d3a5503460f94a1538b/html5/thumbnails/8.jpg)
Formaldehyde, CH2O
••
C HH
O••
••
CHH
O••
1. Draw Lewis structure
2. Determine # of bonds and lone pairs around central atom
3. Electron-pair geometry
4. Molecular geometry
![Page 9: Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around central atom. Axial atomsEquatorial atoms.](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649d3a5503460f94a1538b/html5/thumbnails/9.jpg)
Molecular polarity dependent on two things: Bond polarity Geometry
Dipole Moment Measurement of the molecular polarity
Molecular Polarity
![Page 10: Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around central atom. Axial atomsEquatorial atoms.](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649d3a5503460f94a1538b/html5/thumbnails/10.jpg)
CO2 and H2O
Which one is polar?
![Page 11: Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around central atom. Axial atomsEquatorial atoms.](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649d3a5503460f94a1538b/html5/thumbnails/11.jpg)
![Page 12: Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around central atom. Axial atomsEquatorial atoms.](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649d3a5503460f94a1538b/html5/thumbnails/12.jpg)
Intermolecular Forces (IMF)Noncovalent interactions
Influence propertiesMelting pointBoiling point
Greater the IMF, higher the boiling pointSolubility
Like dissolves likeStructure of complex molecules like
proteins
![Page 13: Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around central atom. Axial atomsEquatorial atoms.](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649d3a5503460f94a1538b/html5/thumbnails/13.jpg)
Beta-carotene
![Page 14: Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around central atom. Axial atomsEquatorial atoms.](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649d3a5503460f94a1538b/html5/thumbnails/14.jpg)
Dipole-Dipole attractionPolar / Polar interaction
More polar molecules greater IMF
5 – 25 kJ/mol (150-1000 KJ/mol – covalent bond)
![Page 15: Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around central atom. Axial atomsEquatorial atoms.](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649d3a5503460f94a1538b/html5/thumbnails/15.jpg)
![Page 16: Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around central atom. Axial atomsEquatorial atoms.](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649d3a5503460f94a1538b/html5/thumbnails/16.jpg)
Polar molecules can induce a dipole in non-polar molecules Polarization
Polarizability Degree to which electron cloud can be distorted to form dipole Higher the molar mass, greater the polarizibility
Dipole / Induced Dipole ForcesPolar / non-polar interaction
![Page 17: Lecture 3111/18/05. Electron Pair Geometries Molecules with only single covalent bonds around central atom. Axial atomsEquatorial atoms.](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649d3a5503460f94a1538b/html5/thumbnails/17.jpg)