Question

A polymeric substance, tetrafluoroethylene, can be represented by the formula ${\left(C_2{F}_4\right)}_x$ where $x$ is a large number. The material was prepared by polymerizing $C_2{F}_4$ in the presence of a sulphur-bearing catalyst that serves as a nucleus upon which the polymer grew. The final product was found to contain $0.012\%S.$What is that value of $x$, if each polymeric molecule contains one sulphur atom? Assume that the catalyst contributes a negligible amount to the total mass of the polymer. $(F=19,S=32)$

Answer 1

${\left(C_2{F}_4\right)}_x=molarmass100x$
$0.012\%s$ present in compound
$100gmC{O}_2⟶0.012gms$
$ygmC{O}_2\to 32gm$
$y=\frac{32\times 100}{0.012}$
$y=266666.6662$
$\cong 266667gm$
As $1{}^{\prime }{s}^{\prime }⟶1$ molecule of polymer
$1mole{}^{\prime }{s}^{\prime }⟶1molepolymer$
molar mass of polymer $=100x.$
$\therefore 1mole{}^{\prime }{s}^{\prime }$ combines with $266667gmpolymer$
$\therefore 100x=266667$
$x=\frac{266667}{100}$
$=2666.67$
$=2667$