CHEMISTRY 150. March 20 th, B. MacLean INSTRUCTIONS:

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1 CHEMISTRY 150 March 20 th, 2013 NAME: B. MacLean INSTRUCTIONS: For questions that involve drawing organic structures, you may use either line-angle structures or condensed structural formulas. Do not present carbon-skeleton structures for your answers. Question Mark Obtained Out of A B1 18 B2 22 B3 12 B4 12 TOTAL:

2 Section A: Multiple choice [2] per correct answer; total = 30 points A1) What factor determines the order of water-solubility for a series of substances? a) intermolecular forces b) intramolecular forces c) boiling points d) molecular shape A2) Which of the following molecules will not undergo oxidation? a) 2-propanol b) 2-methylpropanal c) 2-methyl-2-butanol (3 o alcohol) d) sec-butanol A3) Which of the following reactions would be a condensation reaction? a) saponification b) esterification c. acid + alcohol ester + water c) elimination d) hydrolysis A4) Which of the following compounds would be expected to have the highest degree of solubility in water? a) 1-butanol b) 1-propanol c) 1,3-propane diol 2 OH groups d) propanal A5) Which of the following compounds can undergo a hydration reaction? a) 2-propanol b) butanoic acid c) methyl ethanoate d) 2-butene hydration: addition reaction, involves a reactant with a multiple bond A6) Which of the following is a real/correct IUPAC name? a) 2-methylethanoic acid aka propanoic acid b) 3-butanone aka 2-butanone (or just butanone) c) 2,2-dimethylethanol (aka 2-methyl-1-propanol) d) 2-methylpropanal

3 A7) In benzene, there are -bonds. a) 2 b) 3 c) 6 d) none A8) The two compounds, 3-methyl-2-pentanol and 2-ethyl-1-butanol are a) skeletal isomers b) functional group isomers c) positional isomers (see right) d) not isomers A9) Because of their pleasant aromas, are often included as components of perfumes. a) alcohols b) esters c) ethers d) carboxylic acids A10) Which of the following molecules is a lactone? b a b c d 11) Zaitsev s rule enables one to predict the major product of a(n) reaction. a) condensation b) saponification c) oxidation d) elimination

4 12) Which of the following will not have a positional isomer? a) 2-butanone C=O bond can be in only one location of 4-C chain and still be a ketone b) 2-pentanone c) 1-propanol d) 2-methyl-2-propanol 13) Carboxylic acids and which have the same number of carbons will be functional group isomers. a) ketones b) alcohols c) ethers d) esters 14) When Benedict s reagent is added to a test tube containing an unknown chemical, the test tube takes on a silvery mirror-like appearance. The unknown chemical in the test tube must have been a) a primary alcohol b) a secondary alcohol c) an aldehyde d) a ketone 15) Which of the following molecules will cause the ph of a solution to rise when added? a) ethanol b) ethanoic acid c) sodium ethanoate the only basic substance listed (c. base of carboxylic acid) d) ethanal

5 Section B: Long-answer problems. Answer the following questions in the space provided. B1. Provide names for each of the following structures in the spaces provided: [18 points] 4-bromo-2-pentanone 1,1,1-trichloro-2-propanol IUPAC: 2-methoxypropane common: methyl-2-propyl ether 2-propyl butanoate (also isopropyl, sec-propyl) benzoic acid 3-methylbutanal

6 B2. Complete the following chemical reactions using appropriate chemical structures. Where more than one product structure is possible, show all structures and indicate which should be the major product: [22 points] a H2O H + (cat) b [O] H2SO4/180 o C major c d H + (cat) e [O] f H2O NaOH Na + - g [R]

7 B3. Complete the following diagram by drawing chemical structures for each of the isomers requested in the fields indicated [12 points] this is the only option here any aldehyde of the formula C6H12O positional isomer functional group isomer skeletal isomer ketone with a different C skeleton B4. Arrange the following chemical compounds in order of increasing boiling points (i.e. lowest-tohighest). Important: pay attention to the ordering. [12] methyl propanoate, pentanoic acid, 1-pentanol, hexane, butanoic acid, dimethyl ether dimethyl ether < hexane < methyl propanoate < 1-pentanol < butanoic acid < pentanoic acid LOWEST b.p. HIGHEST b.p. Ethers and alkanes of similar molar mass have similar boiling points; hexane heavier than dimethyl ether Esters have dipole-dipole, but no H-bonding Alcohols are H-bonders Carboxylic acids are stronger H-bonders than alcohols