Number average molecular mass of a polymer that contains 15 molecules with each of mass, 8,000 and 15…
Number average molecular mass of a polymer that contains 15 molecules with each of mass, 8,000 and 15 molecules with each of mass 80,000 is
22,000
33,000
11,000
44,000
Solution
Number average molecular mass of polymer is given by formula:
\(\begin{aligned}
M_n & =\frac{\Sigma N_i M_i}{\Sigma N_i} \\
& =\frac{15 \times 8000+15 \times 80,000}{30} \\
& =\frac{120000+1200000}{30} \\
& =\frac{1320000}{30}=44,000
\end{aligned}\)