Download Organic Chemistry Exam 1 - CHEM 321 - Christopher Newport University - Prof. Jeffrey Carne and more Exams Organic Chemistry in PDF only on Docsity! 1 Department of Biology, Chemistry, & Environmental Science Christopher Newport University CHEM 321 Organic Chemistry Exam 1 – 100 points – 6 pages – Wednesday, September 16, 2009 Honor Pledge: Key (Signature) NAME: KEY 1. (12 points) Draw the best Lewis electron dot structures for each of the following compounds. Show more than one when appropriate. Show all outer-shell electrons as dots including those involved in bonding and any outer-shell non-bonding electrons. Do not use lines. Show charges on specific atoms whenever full formal charges (not partial charges) are present. (a) C2Cl4 (tetrachloroethene) (b) CO2 (carbon dioxide) (c) C2H6O (an ether) (d) CH2N2 (diazomethane) 2 2. (8 points) Consider the structure of urea, a common end product of metabolism, shown below. a. What is the hybridization state of the carbon atom? sp 2 b. What is the approximate N-C-N bond angle in degrees? 120 c. Draw one of the best resonance forms of urea, including any charges if necessary. 3. (6 points) Draw the structure of a hydrocarbon that contains two sp3 hybridized carbon atoms and two sp hybridized carbon atoms. 4. (6 points) Provide one resonance structure for the following compounds using proper electron arrow movement formalism. Be sure to show all charges. 5 10. (8 points) The molecule testosterone is shown below. Answer the following questions regarding its structure. i. Is the carbon indicated by A, 1, 2, 3, or 4? 2 ii. Is the alcohol indicated by B, methyl, 1, 2, or 3? 2 iii. How many H atoms are on the C carbon? One 11. (6 points) Identify the functional group (alcohol, aldehyde, alkane, alkene, alkyne, amide, amine, aromatic/arene, carboxylic acid, ester, ether, or ketone). 6 12. (8 points) A key difference in reactivity between a metal halide such as sodium chloride and an organic halide such as 1-chloropentane is that the former undergoes ionization very readily in water, but the latter does not as indicated below in equations (a) and (b). NaCl H2O Na Cl (a) (b) H3C Cl H2OX H3C CH2 Cl However, an exception is that 5-chloro-1,3-pentadiene does undergo ionization as shown in equation (c). H2O (c) H2C Cl H2C CH2 Cl Provide an explanation as to why the reaction takes place in equation c, but not in equation b. Illustrate your answer with drawings of appropriate structures. In both equations, the carbon with the positive charge is unstable (lacking its octet). In equation (b), this fact prevents the reaction from occurring. In equation (c), that positive charge can be shared between two other carbon atoms through resonance structures. This resonance stabilizes the positive charge and allows for the reaction to occur for 5-chloro-1,3-pentadiene. Name: ____________________________________ Grade: _________
