Polydispersity index is defined as ______ where Mw and Mn are the weight average and number average molecular masses respectively. a) Mw x Mn b) Mw/Mn c) Mn/Mw d) Mw – Mn

Polydispersity index is defined as ______ where Mw and Mn are the weight average and number average molecular masses respectively.

a) Mw x Mn

b) Mw/Mn

c) Mn/Mw

d) Mw – Mn

Solutions

Expert Solution

Answer : b) Wm/Mn

Explanation :

Polydispersity index (PDI) is defines as the ratio of weight average molecular mass to the number average molecular mass. It gives an idea of the homogeneity of the polymer.

Polydispersity index for natural rubber is approximately 1 because there is identical chains and definite mass I.e Wm = Mn.

b) Mw/Mn

Rakesh answered 1 year ago

Next > < Previous

Related Solutions

Explain the terms in detail. a) Number Average Molecular Weight, Mn b) Weight Average Molecular Weight,...

Explain the terms in detail. a) Number Average Molecular Weight, Mn b) Weight Average Molecular Weight, Mw

Calculate Mn & Mw, and the polydispersity index (PI) for the molecular weight data provided below...

Calculate Mn & Mw, and the polydispersity index (PI) for the molecular weight data provided below and graph. Repeat your calculations if the molecular weight data were changed by increasing the frequency (# of chains) of the following molecular weights by 500 for molecular weights of 600, 700, 800, 900, 1000, and 1100 and graph. Explain what happens to the PI and what this means in terms of molecular weight distribution. Input data and graph in Excel or similar graphing...

Molecular weight data for a polymer is tabulated here. (a) Compute the number-average molecular weight (b)...

Molecular weight data for a polymer is tabulated here. (a) Compute the number-average molecular weight (b) Compute the weight-average molecular weight (c) If it is known that this material's degree of polymerization is 710, which one of the polymers listed in Table 4.3 is this polymer? Why? (d) After you do the calculations, consider whether you would consider this material a high molecular weight polymer and why or why not. (e) Give one property that tends to increase with increasing...

Answer about anionic ‘living’ polymerization: (a) What number-average molecular weight (Mn) polystyrene would be formed by...

Answer about anionic ‘living’ polymerization: (a) What number-average molecular weight (Mn) polystyrene would be formed by polymerization of 10 g styrene with 0.1 g of butyl lithium, under complete living polymer system? (b) Suggest three different ways to synthesize polystyrene-b-polybutadiene-b-polystyrene (SBS) tri-block copolymer with controlled block length.

1. A quantity index: a,b,c, or d? and Price Index: a,b,c, or d? a. holds prices...

1. A quantity index: a,b,c, or d? and Price Index: a,b,c, or d? a. holds prices constant and allows quantities to vary b. holds quantities constant and allows prices to vary c. allows both prices and quantities to vary d. holds both prices and quantities constant

Calculate the number average degree of polymerization and the number average molecular weight of an equimolar...

Calculate the number average degree of polymerization and the number average molecular weight of an equimolar mixture of adipic cid and methylene diamond for the extents of reaction 0.5; 0.8; 0.9; 0.95 and 0.995.

Consider the cross: A/a; b/b; C/c; D/d; E/e x A/a; B/b; c/c; D/d; e/e a) what...

Consider the cross: A/a; b/b; C/c; D/d; E/e x A/a; B/b; c/c; D/d; e/e a) what proportion of the progeny will phenotypically resemble the first parent? b) what proportion of the progeny will genotypically resemble neither parent?

Unit costs are defined as a. Marginal costs b. Total costs c. Average costs d. Implicit...

Unit costs are defined as a. Marginal costs b. Total costs c. Average costs d. Implicit costs e. Inverse costs Group of answer choices 2. In the 1890s, German courts were taking a very different approach to cartels and antitrust. What did the German court rule in the pulp cartel case? a. It ruled the cartel was in monopoly that was illegal b. It ruled that cartels were illegal, but that the wood pulp cartel was not a true cartel...

1. Consider a polymer with a number average molecular weight of 6,200 daltons. This polymer is...

1. Consider a polymer with a number average molecular weight of 6,200 daltons. This polymer is made of two different fractions. The first fraction has 40 molecules whereas the second one has 60 molecules with molecular weight of 7,000 daltons. Calculate: (a) The molecular weight of the first fraction of this polymer (1.0 point). (b) The weight average molecular weight (1.0 point). 2. Consider a 18 g polymer sample made of 3 different fractions with the characteristics listed in the...

Q2. A shaft carries four masses A, B, C and D of different magnitude and revolving...

Q2. A shaft carries four masses A, B, C and D of different magnitude and revolving at radii as mentioned below in planes measured from A at 300 mm, 400 mm and 700 mm. The angles between the cranks measured anticlockwise are A to B 450B to C 700 and C to D 1200 . The balancing masses are to be placed in planes X and Y. The distance between the planes A and X is 100 mm, between X...

Subjects