Evaluate the Following Lewis Structure

1) Evaluate the following Lewis structure and determine its legitimacy. a. b. c. d. e. The structure is legitimate. The structure is not legitimate, because the oxygen does not have an octet. The structure is not legitimate, because the formal charges are not shown. The structure is not legitimate, because the middle carbon lacks an octet. The structure is not legitimate, because the leftmost carbon is missing a lone pair. ANS: C 2) Consider the interesting structure below, called a dibromocarbene. The carbon of the dibromocarbene has one lone electron pair and two separate covalent bonds to individual bromine atoms. What is the formal charge on the carbon atom of the dibromocarbene? a. b. c. 2 1 d. e. 1 2 d. e. C6H11NO2 C6H13NO2 0 ANS: C 3) What is the molecular formula of this compound? a. b. C6H12NO2 C5H12NO2 c. C5H11NO2 ANS: D 4) Which condensed formula contains an aldehyde functional group? a. CH3COCH3 d. CH3CH2OH b. CH3CO2CH2CH3 e. CH3CHO c. CH3CH2CH2COOH ANS: E 4) Naltrexone is an FDA-approved treatment for alcoholism that targets the mu opioid receptor. Name four functional groups that are present in naltrexone. a. b. c. amine, phenol, aldehyde, ether amine, phenol, amide, alcohol amine, phenol, ketone, alcohol d. e. ether, ketone, amide, alcohol ketone, phenol, alcohol, ester ANS: C 5) Which functional group is present in the following molecule? a. b. c. amine alcohol ketone d. e. ester ether 6) What is the IUPAC name for the following molecule? a. b. c. 3,3-dichloro-5-bromohexane 3-chloro-3-chloro-5-bromohexane 2-bromo-4,4-dichlorohexane d. e. 3,3-chloro-5-bromohexane 4,4-dichloro-2-bromohexane ANS: C 7) .What is the IUPAC name for the following molecule? a. b. c. 4-butyl-6-ethyloctane 3-ethyl-5-butyloctane 5-propyl-7-ethylnonane d. e. 3-ethyl-5-propylnonane 5-propyl-7-ethyldecane ANS: D 8) The carbon atoms in the molecule below are labeled 1–8. Which C—C—C bond angle in the molecule would be approximately 120? a. b. c. C1—C2—C3 C2—C3—C4 C4—C5—C6 d. e. C5—C6—C7 C6—C7—C8 d. e. tetrahedral bent d. e. tetrahedral bent ANS: B 9) What is the electronic geometry for the indicated atom? a. b. c. linear trigonal planar trigonal pyramidal ANS: D 10) What is the electronic geometry for the indicated atom? a. b. c. linear trigonal planar trigonal pyramidal ANS: B 11) Which of the following molecules possesses at least one polar covalent bond but does not have an overall net molecular dipole? a. b. c. CH4 CHCl3 CH2Cl2 d. e. CCl4 CH3CH3 ANS: D 12) Which C—C bond in the following molecule is formed from the overlap of an sp3 orbital and an sp2 orbital? a. b. c. the C1—C2  bond the C1—C2  bond the C3—C4  bond d. e. the C3—C4  bond the C4—C5  bond Written questions 1) Consider two solvents that are commonly used for organic chemistry reactions: CH 2Cl2 and CCl4. It is interesting that studies have shown that one of these solvents is polar and one is nonpolar. Draw valid Lewis structures for these two molecules. Show bond dipoles and both partial charges ANS: Although CCl4 has individual bond dipoles, the vector sum of the bond dipoles is zero. This means that CCl4 is a nonpolar molecule. CH2Cl2 has two bond dipoles that do not cancel; thus, CH2Cl2 is a polar molecule. The electrostatic potential map of CH2Cl2 would show that the electron density in each of the C–Cl bonds is shifted toward the Cl atom. 2) Draw all possible resonance forms for anisole using appropriate arrow notation. Which resonance structure is most stable? Which is least stable? Draw the resonance hybrid for anisole, indicating all partial charges. ANS: The neutral structure is most stable. The two structures with the partial negative charge closest to the oxygen are equal in energy. These structures are also more stable than the structure with the charges farther apart; thus, they contribute a greater degree to the hybrid. 3) 3) Sodium chloride, an ionic compound, is highly water soluble but minimally soluble in the polar aprotic solvent dimethyl sulfoxide (DMSO). Why?