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 following table.

(a) Calculate the number average molecular weight of this polymer (2.0 points).

(b) If the dispersity of this polymer is 2.5, calculate its weight average molecular weight (1.0 point).

Number of molecules (mol)	Weight (g)
1.0 x 10-3	5
1.5 x 10-3	10
0.5 x 10-3	3

3. Consider a polymer with the characteristics described in the following table.

(a) Calculate the number average molecular weight of this polymer (2.0 points).

(b) Calculate the weight average molecular weight of this polymer (2.0 points).

(c) Calculate the polydispersity index (0.5 point).

(d) Is the molecular weight distribution narrow or wide? (0.5 point)

Molecular weight (g/mol)	Mole fraction
150,000	0.10
175,000	0.15
200,000	0.30
225,000	0.25
250,000	0.20

Expert Solution

queen_honey_blossom answered 2 years ago

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