Answer :
(a) The repeat unit is, styrene
(b) The number-average molecular weight is, 2392000 g/mol
Explanation :
First we have to calculate the repeat unit molecular weight of polystyrene.
As, the repeat unit is, styrene having chemical formula [tex]C_8H_8[/tex]
Molecular weight of repeat unit = 8 × C + 8 × H
Molecular weight of repeat unit = 8 × 12 g/mol + 8 × 1 g/mol
Molecular weight of repeat unit = 104 g/mol
Now we have to calculate the number-average molecular weight.
Number-average molecular weight = Average repeat molecular weight × Degree of polymerization
Number-average molecular weight = (104 g/mol) × (23000)
Number-average molecular weight = 2392000 g/mol
Thus, the number-average molecular weight is, 2392000 g/mol
