Answer:
a) the repeat unit molecular weight of PTFE MW = 100.015 g/mole
b) the number-average molecular weight for a PTFE for which the degree of polymerization is 10,000 щₙ = 1000150 g/mole
Explanation:
Given that;
PTFE which is also called Polytetrafluoroethylene
structure of repeat unit of Polytetrafluoroethylene
(C2F4)n
a)
To compute the repeat unit molecular weight
we say
MW = 2( atomic weight of C ) + 4( atomic weight of F)
MW = 2 (12.0107) + 4 ( 18.9984)
MW = 100.015 g/mole
therefore the repeat unit molecular weight of PTFE MW = 100.015 g/mole
b)
To compute the number-average molecular weight for PTFE of which the degree of polymerization is 10,000
we say
DP = щₙ / MW
where щₙ is the number of average molecular weight,
MW is the repeat unit molecular weight give as 100.015 g/mole
DP is degree of polymerization which is 10,000
Now we substitute
10,000 = щₙ / 100.015
щₙ = 10,000 × 100.015
щₙ = 1000150 g/mole
Therefore the number-average molecular weight for a PTFE for which the degree of polymerization is 10,000 щₙ = 1000150 g/mole
