(c) What is the value of the degree of polymerization n of isotactic PB with a molecular weight of 3.091×105 g/mol?
http://en.wikipedia.org/wiki/Polybutylene
To determine the value of the degree of polymerization (n) of isotactic PB, you need to use the relationship between molecular weight and degree of polymerization.
The molecular weight of a polymer (Mw) is related to the degree of polymerization (n) by the following equation:
Mw = n * Mp
Where Mw is the molecular weight, n is the degree of polymerization, and Mp is the average molecular weight of the repeating unit.
To solve for n, rearrange the equation:
n = Mw / Mp
Given that the molecular weight (Mw) of isotactic PB is 3.091×105 g/mol, you need to know the average molecular weight of the repeating unit (Mp) of the PB polymer. This information is usually provided in the problem statement or can be obtained from experimental data.
Once you have the value of Mp, substitute it into the equation to calculate the value of n.
Note: The average molecular weight of the repeating unit is specific to the polymer being analyzed. In this case, you would need the average molecular weight of the repeating unit of isotactic PB to obtain the precise value of n.