It is seen from the given balanced equation of the repacement reaction that every mole of (CH2)n requires total 2nmol F2.Here n mol goes to replace hydrogen and n mol goes to form 2n mol HF and thus one mole of (CF2)n is formed.
Molar masses of
F2→38g/mol
(CF2)n→50ng/mol
Fluorine required for the production of 50ng (CF2)n is 2n mol or 76ng
So to prodoce 1kg (CF2)n we rrequire 76n50nkg=1.52kg Fluorine, if not recovered from HF produced as byproduct.
As 50% F2 goes to form the byproduct HF,then its recovery will diminsh the net consumption by 50% and the consumption of Flurine for productio of 1kg (CF2)n then will be 50%of1.52kg=0.76kg
