I think it's b
let's work out empirical formula:
CO2 + H20 is CH2O3
the mass of CH2O3 is 12+2+(16×3)=62
work out mass of CO2
mass=number of moles × relative formula mass
mass=1.5 mol × 44 = 66
work out mass of H20
mass=number of moles × relative formula mass
mass=2 × 18 = 36
so the molecular formula is 66+36=102
to calculate simplest molecular formula:
molecular formula mass/empirical formula mass
102/62=2 (rounded to nearest whole number)
back to the empirical formula which is CH2O3
multiply each element by 2 which is
C2H4O6
answer:C2H4
not 100% sure though, but I hope it's been of some use to you:)