Updated September 3, 2021 For those of you who have already had me, you know that this is the page to come to to get assignments, labs, weekly announcements and summaries. Past weeks announcements will be placed in the Quarter 1 Archives drop-down menu.
Do make sure you have printed out both the O-Chem Syllabus and Weekly Pacing Guide.
This week we were able to barely discuss Formal Charges and Oxidation numbers. Recollect that our interest in determining these values on individual atoms within molecules is so we can gain some idea as to "hotspots" for chemical reactivity. Such hotspots arise whenever there is a charge separation due to electronegativity differences between bonding atoms (see chart below).
For more assistance on this, please refer to video linked right, covering Section 1.9 from your text.
What to Expect in Week 3
I hope this coming week, we can get through drawing resonance structures and functional groups. Recollect what the function of resonance structures is: Lewis structures in inadequate in representing the electronic behavior and charge distribution in certain types of molecules, so resonance contributors are written, with each conveying some bit of information about the location of positive and negative charges. A resonance hybrid is a representation of all the resonance contributors combined, showing the distribution of partial positive and partial negative charges.
Note in the image below, four different resonance contributors to the eight-carbon alkene. From all these contributors, what do you think the resonance hybrid would look like?
Please take time to watch the two videos below, before class on Thursday; they will help you in drawing resonance contributors and hybrids.
As a reminder, you will have to memorize the structures of about 17 different functional groups, as they appear below. Functional groups represent specific structures within molecules that impart a certain type of reactivity. Typically whenever a reaction occurs, it occurs wherever there is a functional group.
Check-off List of Things to Do:
In order to be adequately prepared for classes next week, please make sure you do the following by: Tuesday, September 7th, 2021
Labor Day (Boo hoo!!)
Thursday, September 9th, 2021
Turn in: Lab 1 - Writing Lewis Structures
Turn in: Lab 2 - Formal Charges
Watch videos for Sections 1.9, 1.10, and 1.11
Prepare for Quiz #3, covering resonance structures - we will do together