A sample of hexane was cracked. A sample of 50cm³ of gas was produced. The gas decolorized 4cm³ of 0.23moldm–³ solution of bromine. What % of alkenes was produced?

Answer 1

millimoles Br2 used = mL x M = 4*0.23 = approx 0.9
1 mol Br2 adds to 1 mol alkene; therefore, mmols Br2 alkene = approx 0.9.
mols in 50 cc at stp = 50/22,400 and millimols = 50*1000/22,400 = approx 2.
% alkene = (mmols alk*100/mmols gas) = ?
% alk = mols alkene/

Answer 2

thanks Drbob222