A compounds empirical formula is HO. If the formula mass is 34 amu, what is the molecular formula?

1 Answer
Nov 23, 2016

#"Molecular formula"# #=# #H_2O_2#.

Explanation:

The molecular formula is always a whole number mulitple of the empirical formula, and of course the multiple might be #1#.

So here, #("Molecular formula")# #=# #("Empirical formula" xx n)#

And thus,

#("Molecular mass")=34*g*mol^-1=nxx(1.008+15.999)*g*mol^-1#

Clearly #n=2#, and the molecular formula of hydrogen peroxide is #H_2O_2#.

What is the oxidation number of oxygen in this molecule?