1. Resonance, bond strength and Length

2. Visit: https://checkin.ics.uci.edu/https://checkin.ics.uci.edu/ Log in and select Chem 1A. When prompted, type the word of the day: bonds Ensure when asked if you will share your location you select “allow”. Visit: https://learningcatalytics.com/https://learningcatalytics.com/ Sign in MasteringChemistry account name When prompted, type session ID: 35789297 Please turn off all downloads. You can usually pause them by clicking on them and clicking pause. Facebook and youtube are officially banned during class time (this is not me micromanaging, it’s a legit internet issue as told to me by OIT). Remember back 5 rows of even side are no seating zones Visit: https://checkin.ics.uci.edu/https://checkin.ics.uci.edu/ Word of the day: learning Ensure when asked if you will share your location you select “allow”. LearningCatalytics: session ID: 35789297

3. [HCO 2 ] - Any common octet breaking atoms? How many electrons are present? What is the central atom? Draw a skeletal structure Add electrons: do you have enough to give all atoms octets? Yes? Then minimize formal charges if needed. No? Then add double bonds until you have enough electrons. Is it one that is typically found to have less? Is there any reason you chose those double bonds rather than placing it elsewhere? No? Then draw resonance structures to show all equally likely structures Label each with the formal charge C H O O C H O O +0 Visit: https://checkin.ics.uci.edu/https://checkin.ics.uci.edu/ Word of the day: learning Ensure when asked if you will share your location you select “allow”. LearningCatalytics: session ID: 35789297

4. C H O O C H O O +0 What is the charge on each oxygen? Hint: they are the same! What is the bond order of the CO bond? Hint: they are the same! Visit: https://checkin.ics.uci.edu/https://checkin.ics.uci.edu/ Word of the day: learning Ensure when asked if you will share your location you select “allow”. LearningCatalytics: session ID: 35789297

5. O3O3 Any common octet breaking atoms? How many electrons are present? What is the central atom? Draw a skeletal structure Add electrons: do you have enough to give all atoms octets? Yes? Then minimize formal charges if needed. No? Then add double bonds until you have enough electrons. Is it one that is typically found to have less? Is there any reason you chose those double bonds rather than placing it elsewhere? No? Then draw resonance structures to show all equally likely structures Label each with the formal charge 6(3)=18 electrons. O O O Short 2 electrons Need one bond O O O O O O +0 +1 +0 +1 Visit: https://checkin.ics.uci.edu/https://checkin.ics.uci.edu/ Word of the day: learning Ensure when asked if you will share your location you select “allow”. LearningCatalytics: session ID: 35789297

6. O O O O O O +0 +1 +0 +1 What is the charge on the outside oxygens? Hint: they are the same! What is the bond order of the bonds? Hint: they are the same! Visit: https://checkin.ics.uci.edu/https://checkin.ics.uci.edu/ Word of the day: learning Ensure when asked if you will share your location you select “allow”. LearningCatalytics: session ID: 35789297

7. [SO 3 ] 2- 6*4+2=26 electrons S O O O +1 S O O O +0 +0 S O O O +0 S O O O +0 +0 Bond order: 4 bonds divided by 3 structures 4/3 Charge: -2 total charges divided by 3 atoms -2/3 All have octet, Can we minimize formal charge? Visit: https://checkin.ics.uci.edu/https://checkin.ics.uci.edu/ Word of the day: learning Ensure when asked if you will share your location you select “allow”. LearningCatalytics: session ID: 35789297

8. Line Structures: CH 3 CHCHCOOH Rules The end of a line, or a corner is a carbon All hydrogens attached to a carbon are assumed to be there. Do not draw them. Don’t forget the three hydrogens attached to the carbon at an end of a line are there! Heteroatoms: aka atoms other than C and H, need to be written in. All hydrogens attached to heteroatoms must be drawn in. H3C---CH2---CH2----CH3 H3C---CH---CH----CH3 H3C---CH---CH----COOH OH O Visit: https://checkin.ics.uci.edu/https://checkin.ics.uci.edu/ Word of the day: learning Ensure when asked if you will share your location you select “allow”. LearningCatalytics: session ID: 35789297

9. Line Structures: NH 2 CH 2 CH(OH)CH 3 Rules The end of a line, or a corner is a carbon All hydrogens attached to a carbon are assumed to be there. Do not draw them. Don’t forget the three hydrogens attached to the carbon at an end of a line are there! Heteroatoms: aka atoms other than C and H, need to be written in. All hydrogens attached to heteroatoms must be drawn in. H2NH2N H 2 N---CH2---CH2----CH3 H2NH2N H 2 N---CH2---CH(OH)----CH3 OH

10. BENZENE C 6 H 6 6-membered ring Draw the lewis structure Be sure to include any resonance structures Draw the line structure Be sure to include any resonance structures C 6 H 12 C6H6C6H6 Add double bonds to decrease, Hydrogens present.