Answer / kangchuentat

POLYMER ENGINEERING - ANSWER 24.1 : (i) Number average molecular weight = Ma Xa + Mb Xb + Mc Xc = 14 x 0.5 + 16 x 0.3 + 18 x 0.2 = 15.4 kg / mol. (ii) Weight average molecular weight = (Ma Xa Ma + Mb Xb Mb + Mc Xc Mc) / (Ma Xa + Mb Xb + Mc Xc) = (14 x 0.5 x 14 + 16 x 0.3 x 16 + 18 x 0.2 x 18) / 15.4 = 15.558 kg / mol. (iii) Polydispersity = [ answer in (ii) ] / [ answer in (i) ] = 15.558 / 15.4 = 1.0103. (iv) Degree of polymerization = (Ma Xa + Mb Xb + Mc Xc) / (molecular weight of repeat unit) = (15.4 kg / mol) / (12 g / mol) = 1.283 k = 1283. The answer is given by Kang Chuen Tat; PO Box 6263, Dandenong, Victoria VIC 3175, Australia; SMS +61405421706; chuentat@hotmail.com; http://kangchuentat.wordpress.com.

How much will be the increment for postal assistant yearly?

0 Answers  

---

Explain what are some good uses of low-grade steam at 12 atm and 1920c?

0 Answers  

---

hi.i m student of chemical engg. and studying in 5 th sem.how can i improve my technical knowledge..can u sugest me a link like book or any website..?

3 Answers  

---

which book is better for written test of a refinery or a chemical industry-o.p gupta or DR.RAM PRASAD?

2 Answers  

---

What are the advantages of using gear pumps?

0 Answers  

---

Explain what information is needed to specify a mixer?

0 Answers  

---

How can I treat a waste stream containing both hexavalent chromium and arsenic?

0 Answers  

---

BIOCHEMICAL ENGINEERING INSTRUMENTATION - EXAMPLE 29.3 : In thin layer chromatography (TLC), let retention factor Rf = (distance traveled by solute) / (distance traveled by solvent). Silica gel is used as stationary phase which is more polar than the hexane solvent as mobile phase. If the Rf values of 3 solutes A, B and C are 1.5, 0.75 and 1 respectively, compare the polarities of A, B and C with reasons.

1 Answers  

---

an anybody provide me the HPCL apptitude papers?am having the test on this feb 27th 2008 so plz [Send This Question to Your Friend] please send me hpcl placement papers both technical and apptitude.. please

3 Answers   HPCL, NTPC,

---

Are fin tubes necessary for steam heating a liquid?

7 Answers   IOCL,

---

What are the different ways in which solids can be blended?

0 Answers  

---

Question 77 - The molecular weights M in kg / mol of 3 different monomers a, b and c in a polymer are Ma = 14, Mb = 16 and Mc = 18, with their respective quantities in N units having the ratio of Na : Nb : Nc = 2 : 3 : 5. (a) Find the numerical average molecular weight of the polymer by using the formula (Ma Na + Mb Nb + Mc Nc) / (Na + Nb + Nc). (b) Find the weighted average molecular weight of the polymer by using the formula (Ma Na Ma + Mb Nb Mb + Mc Nc Mc) / (Ma Na + Mb Nb + Mc Nc). (c) Calculate the polydispersity Q by using the answer in (b) divided by answer in (a). (d) Find the volumetric average molecular weight of the polymer by using the formula (Ma Na Ma Ma + Mb Nb Mb Mb + Mc Nc Mc Mc) / (Ma Na Ma + Mb Nb Mb + Mc Nc Mc). (e) Estimate the polydispersity Q by using the answer in (d) divided by answer in (b).

1 Answers  

---