Chem460 Exam-1 2010 - What can you say about the number of...

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CHEM460 EXAM #1 Name . Fall, 2010 Professor Sasaki 100 points TOTAL Good Luck! Note: Only answers in the box will be graded. 1. (30) (a) Calculate to the 3rd decimal places the exact mass and theoretical M+1 and M+2 ratios for C 5 H 10 O 3 . Clearly show your work. (i) Exact mass. (ii)M+1 and M+2 ratios. (b) Electrospray (ion spray) MS of a compound showed a peak at m/z = 450. The peak was assigned to [M+10H] 10+ . What is the molecular weight of the compound? Show your calculation.
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CHEM460 page 2 2. (35) Based upon the given data, answer the following questions. Uncertainties for mass is ± 0.005 amu. Uncertainties for ratios are ± 0.005 %. Clearly show your work. molecular ion: 146.076 (100%) M+1: 12.066% M+2: 4.336% (a)
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Unformatted text preview: What can you say about the number of nitrogens in the molecular formula of this compound? (b) This compound MAY contain C, H, N, O, Cl, Br, S and Si. Which element(s) can you rule out based on the M+2 ratio value. Briefly explain your reasoning. (c) Determine the molecular formula of this compound. Clearly show your work. Make sure that you verify your molecular formula by calculating the exact mass and theoretical M+1 and M+2 ratios. CHEM460 page 3 3. (35) (a) The following is EI-MS of one of the pentanol isomers (MW = 88.1). Determine the structure of the compound. Provide a brief explanation. (b) Briefly explain how you would use mass spectroscopy to distinguish the following two compounds. O and O...
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This note was uploaded on 01/18/2012 for the course CHEM 460AB taught by Professor Sasaki during the Fall '11 term at University of Washington.

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Chem460 Exam-1 2010 - What can you say about the number of...

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