Question

A copolymer consisting of vinyl acetate and vinyl chloride has a molar molecular mass of 10 000 g/mol and a degree of polymerization, DP, of 200. The molecular weight of a vinyl chloride mer is 62.5 g/mol. The molecular weight of a vinyl acetate mer is 86 g/mol. The mole fraction of vinyl chloride is most nearly O A. 0.1 LOB. 0.3 loc. 0.5 OD. 0.6

Answer 1

Answer:

C. 0.5

Explanation:

Given that

Molecular mass= 10,000 g/mol

DP= 200

Molecular weight of vinyl chloride = 62.5 g/mol

Molecular weight of vinyl acetate =  86 g/mol

Lets take mole fraction of vinyl chloride is x

And mole fraction of vinyl   acetate is (1-x)

As we know that

Mass = number of mole x molecular wight

For vinyl chloride

Mass of  vinyl chloride=62.5 x

For vinyl acetate

Mass of  vinyl acetate =86(1-x)

Total mass(mass of monomer) = 62.5 x + 86 (1-x)  ----1

We know that total weight of polymer given as

total weight of polymer = DP x Mass of monomer

          10,000 =200(62.5 x + 86 - 86 x)

23.5 x = 36

x=1.53

This can not be possible .because be assumed that x is less than 1.

If we replace 10,000 by 15,000 then

 15,000 =200(62.5 x + 86 - 86 x)

75 =62.5 x + 86 - 86 x

x=0.46

x=0.5

So the answer C is correct.