# Converting from Grams to Molecules

I was doing some problems from the textbook on converting between units using dimensional analysis and I came across this problem.

A vat of Hydrogen Peroxide ($\ce{H2O2}$) contains 455 grams of oxygen atoms. How many molecules of ($\ce{H2O2}$) are in the vat?

Sorry if I didn`t format the question correctly, I am a still a newbie. But how would I set this up? I would not like the answer to this question but I would like some input on how would I get how many molecules of hydrogen peroxide from grams of oxygen atoms? Any help would be much appreciated. Thanks in advance!

A vat of Hydrogen Peroxide ($\ce{H2O2}$) contains 455 grams of oxygen atoms. How many molecules of ($\ce{H2O2}$) are in the vat?

1. How many moles of oxygen atoms are in 455 gms of oxygen atoms? Let's call the answer $x$.
2. How many moles of $\ce{O2}$ are in $x$? Let's call the answer $y$.
3. How many moles of $\ce{H2O2}$ could you make from $y$ moles of $\ce{O2}$? Let's call the answer $z$.
4. 1 mole of any substance contains Avogadro's number of molecules. How many molecules are in $z$ moles?
• Thanks for the response. For #3, is the answer 14.21 moles of Hydrogen Peroxide? – ToxicTechnetium Sep 25 '14 at 19:45
• And is the answer to the question 8.56 * 10^24? – ToxicTechnetium Sep 25 '14 at 19:46
• @ToxicTechnetium You got it! – ron Sep 25 '14 at 19:48