Homework |
Chemistry 595 |
Spring 2007 |
Professor Dadmun |
| Assignment #1 | Due Thur. Feb. 15 |
From the text:
Questions 1.28, 1.40, and 1.41
1.) The following are the measured diameters of a series of spheres:
Number of Spheres |
Diameter (cm) |
2 |
1 |
3 |
2 |
4 |
3 |
2 |
4 |
Calculate the number average (Dn) and weight average (Dw)
diameter of this collection of spheres.
2.) The following Viscosity Data was obtained for polystyrene in toluene at 30 °C
conc (g/dL) |
t (sec) |
0 |
65.8 |
0.54 |
101.2 |
1.08 |
144.3 |
1.62 |
194.6 |
2.16 |
257 |
Determine the value of the Huggins constant, kH, the intrinsic viscosity of the sample and the viscosity average molecular weight of the polymer. You should be able to find K and a for this polymer pair fairly easily.
3.) Given a Size exclusion Chromatography curve that has been calibrated to provide weight of component with molecular weight Mi vs Mi, show explicitly how to determine the number average and weight average molecular weight of the sample from this data.