Ch 334 Code _________ Midterm #1 October 13, 2006 1. (3 pts) Which of the following would not be a Lewis structure of CH3NO2? Circle your choice. 2. (3 pts) Which is the appropriate conversion from condensed formula to skeletal formula? Circle the correct answer. CH3CHClCH2CH(CH3)2Page 2 of 8 3. (3 pts) Convert the following skeletal formula to a condensed formula. Place your answer in the box provided. 4. (4 pts) Circle any structures below that are resonance structures for the anion in the box. 5. (10 pts) Determine whether the following pairs of compounds are isomers, resonance structures or neither. Lone pairs are not drawn on these structures. Place your answers in the blanks provided. ______________________ ______________________ ______________________Page 3 of 8 ______________________ ______________________ 6. (3 pts) Circle the drawing that best describes the resonance hybrid for the resonance structures shown in the box. 7. (6 pts) Indicate the formal charge on the B, O, and F atoms in the following compound: B ________ O _________ F _________Page 4 of 8 8. (5 pts) Circle any of the following species which contain a carbon atom with a +1 formal charge. (All nonbonded electrons and electron pairs have been drawn in.) 9. (3 pts) Circle any of the following species has a trigonal planar structure with 120° bond angles around the labeled carbon atom. 10. (3 pts) How many hydrogens are present around each of the indicated carbon atoms? Ca ______ Cb ______ Cc ______ 11. ( 3 pts) Which of the following statements correctly describes the typical bonding of carbon, nitrogen and oxygen in organic molecules? Circle it. A. Oxygen participates in 2 covalent bonds and has 2 lone pairs of electrons B. Nitrogen participates in 2 covalent bonds and has 1 lone pair C. Carbon participates in 4 covalent bonds and has no lone pairs D. Oxygen participates in 2 covalent bonds and has 2 lone pairs of electrons and Nitrogen participates in 2 covalent bonds and has 1 lone pair E. Oxygen participates in 2 covalent bonds and has 2 lone pairs of electrons and Carbon participates in 4 covalent bonds and has no lone pairsPage 5 of 8 12. ( 3pts) Consider the organic molecule drawn below. Describe which orbitals are used to form the C=O bond. Since there are two bonds, you must identify two different sets of orbitals. Circle the best response. A. Csp2 - Osp2 and Cs - Op B. Csp - Osp and Cp - Op C. Csp2 - Osp2 and Cs - Os D. Csp2 - Osp2 and Cp - Op 13. (4 pts) How many sigma and pi bonds are there in H2C=CH-C≡N ? There are ______ sigma bonds and ______ pi bonds. 14. (4 pts) Consider the following molecule having three labeled protons, Ha, Hb, and Hc. Rank these protons in order of increasing acidity. The most acidic hydrogen labeled is ________ The least acidic hydrogen labeled is _________ 15. (4 pts) Circle the compound that is the strongest acid. 16. (3 pts) Circle any of the following that can be a Lewis acid.Page 6 of 8 17. (4 pts) Complete the following acid-base reaction equation. Label the acids and bases on each side of the equation. 1 18. (2 pts) What is the pKa for a compound with Ka = 10-14? _____________ 19. (4 pts) Which pKa indicates the weakest acid? Circle the correct response. A. pKa = -3 B. pKa = 5 C. pKa = 24 20. (3pts) Does equilibrium lie on the right or left in the following reaction? _________________ 21. (3 pts) Draw an arrow to the electrophilic site in each of the following molecules. 22. (3 pts) Draw an arrow to the nucleophilic site in the following molecules.Page 7 of 8 23. (3 pts) Circle the compound that is the strongest base. A. NH2- B. OH- C. Cl- D. NH3 E. I- 24. (3 pts) Circle the compound which is the strongest Bronsted-Lowry acid? A. H2S B. H2O C. NH3 25. (2 pts) Give two requirements a molecule must meet to be a polar molecule. a. b.Page 8 of 8 26. (5 pts) Determine if the following molecules will be polar or non-polar. Give a reason for your choice. No correct reason, no credit. Polar or Non Polar Reason a. H2O b. CO2 c. Cl2O d. BeClF e. CH4 27. (4 pts) Identify the major functional groups in the following molecules. The best response is : ________ 1. A: aldehyde; B: amine; C: ether; D: ketone 2. A: carboxylic acid; B: amine; C: ether; D: ketone 3. A: carboxylic acid; B: amine; C: ester; D: ketone 4. A: carboxylic acid; B: alkane; C: ether; D: ketone 5. A: carboxylic acid; B: amine; C: ether; D: