Answer
$DP = 4,847.78 \approx 4,848$
Work Step by Step
Given:
The number-average molecular weight of a polystyrene is 500,000 g/mol.
Required:
degree of polymerization
Solution:
From Table 14.3, each repeat unit consists of 7 hydrogens and 8 carbons. Computing the repeat unit molecular weight:
$m = 8(A_{C}) + 7(A_{H})= 8(12.011 g/mol) + 7(1.008 g/mol) = 103.14 g/mol$
Using Equation 14.6:
$DP = \frac{M_{n}}{m} = \frac{500,000 g/mol}{103.14 g/mol} = 4,847.78 \approx 4,848$
