Quiz 7 potential problems ChE 350 sp10

Quiz 7 potential problems ChE 350 sp10 - Sample question...

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Sample question for ChE 350 Spring 2010 Quiz 7 Name:________________________ 1 1. The number-average molecular weight of a poly(styrene-butadiene) alternating copolymer is 1,350,000 g/mol; determine the average number of styrene and butadiene mer units per molecule. (The molecular weights of carbon and hydrogen are 12 g/mol and 1 g/mol, respectively.) Answer: _______________________ 2. Using the data provided in the table for a polymer sample, answer the following questions: (a) Determine the number average molecular weight: _____________________ (b) Determine the weight average molecular weight: ______________________ (c) Determine the polydispersity index: ________________________ Number of Molecules Mass of each Molecule 1 800,000 3 750,000 5 700,000 8 650,000 10 600,000 13 550,000 20 500,000 13 450,000 10 400,000 8 350,000 5 300,000 3 250,000 1 200,000 3. (a) Write the chemical formula for the polymer, polyethylene.________________
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Unformatted text preview: Sample question for ChE 350 Spring 2010 Quiz 7 Name:________________________ 2 (b) What is the monomer molecular weight of polyethylene?: ___________________ (c) What is the average degree of polymerization for a sample of polyethylene with a number average molecular weight of 280,000? ______________________ 4. Molecular weight data for a polymer are tabulated below. (a) Fill in the blanks in the table, calculating mole fraction, weight fraction, x i M i and w i M i . (b) Compute the number average molecular weight: _____________________ (c) Compute the weight average molecular weight: _______________________ (d) Compute the polydispersity index: _____________________________ (e) Would this polymer be considered monodisperse?________________________ Number of Molecules Mass of each Molecule (M i , g/mol) Mole Fraction (x i ) Weight Fraction (w i ) x i M i w i M i 50 4000 40 10000 30 20000 20 50000 10 100000...
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This note was uploaded on 12/13/2011 for the course CHE 350 taught by Professor Sanchez during the Spring '08 term at University of Texas.

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Quiz 7 potential problems ChE 350 sp10 - Sample question...

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