Question

Problem: 1.3: Calculate the number average and weight average relative molecular mass for a sample of polystyrene made by blending eight separate fractions, each of which has a very narrow molecular mass distribution, as follows: RMM | Weight/ g 15k 0.10 27k 0.19 39k56k78k 0.25 0.17 0.12 104k120k 0.08 0.06 153k 0.04 | Solution:

Answer 1

wil page 9 - Answer: 13 -According to the given infamation, to calculate the number average of weight average molecular mase. Given, RMM weight(91 Miwi 15000_0:10 15000X041 21500 (01)2 :01 2000 0.1991000 X0:192 5130_10.1997 = 0.036 39000 0.95 39000 X0:25: 9.750 0.95.42 0.0625 56000011 56000X0.17 9530 10:12V2.0.0189_ -180000:12 :18000X0.12. 9360 (0:12). 0:00 41040000.08_104000 X 0.066 8320 (0:08) = 0.0064 120006 0.06 120000X0:06 4200 (0.06192 0.0036 153000.10.04 153000XD.Q4: 6120 16.09370.0016 total= 100 total 2 56900 total a 0.1635 *calculate average (number) molecular weight (Mn);- Mn = {wili 1. Iwi .. 56900 56900 lis numben average molecular weight - 56900

-* calculate weight -nvesnage molecular weight (red): page @ How = E hoor mi E cini I hOiN HER ( 15000X0.011+ (2.7000X00361)+ (39000x 0.06as) +(56000 X 0.0289)+ (18000 X D10144) +104000X 0.0064) + (120000X 0.0036) +(0.0016 *153000) a 150 + 97404+ 24357.5+1618.47112312 + 6656+432 + 204.8 2.7646.2 .. weight average Molecular weight = 7646.2.