CHEMISTRY COMMUNITY

I am looking at question number two on the midterm and I am confused by the solution. For the ratios it says they are 1.4:1.2:1
To get 1.4 you divide the moles of co2 by the moles of o2
But to get 1.2 you have to divide the grams of H2O by the moles of O2

Why would you do this?

for that question the ratios are not derived from the overall molecules. What you have to do is find the moles of C in CO2, the moles of H in H2O and then add those two together. This number will be subtracted from 1 because that is the weight of your unknown compound, giving you the grams of O which you can turn into moles. From there you divide each by the smallest number leading to the ratio of 1.4:1.2:1