M2_3-student - Unit 3 How do we determine structure? Module...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Chemistry XXI Unit 3 How do we determine structure? Module 2: Predicting Geometry Central goal: To deduce the Lewis structure of molecules and predict their three dimensional geometry based on the analysis of the number and type of valence electron pairs surrounding each atom.
Background image of page 1

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

View Full DocumentRight Arrow Icon
Chemistry XXI The Challenge The properties of a substance are determined by the structure of its molecules. How can we predict molecular geometry given information about atomic composition and atom connectivity ? Molecular structure depends on: Atomic Composition Atom Connectivity Molecular geometry Aspirin Modeling How do I predict it?
Background image of page 2
Chemistry XXI We have seen that when two atoms of nonmetallic elements combine, their valence electrons are reorganized. The number of covalent bonds that are formed are determined by the most stable electron configurations ( full valence shell ). Electron Distribution We can use the octet rule (or full valence shell rule) to make predictions about how electrons will distribute among the different atoms in a molecule. O 2 O O O O N N N N Useful Tool: Lewis Electron-dot Structures
Background image of page 3

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

View Full DocumentRight Arrow Icon
Chemistry XXI 1. Count valence electrons : H = 1 and O = 6 Total = ( 2 x 1 ) + 6 = 8 valence electrons This electrons will organize in 4 pairs ( spin pairing to minimize energy) There are some simple rules that facilitate the creation of Lewis structures. Let’s illustrate them Lewis Structures 1. Choose the central atom; never
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 20

M2_3-student - Unit 3 How do we determine structure? Module...

This preview shows document pages 1 - 5. Sign up to view the full document.

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