You find that 7.36g of a compound has decomposed to give 6.93g of oxygen. the only other element in the compound is hydrogen. if the molar mass of the compound is 34.0g/mol, what is its molecular formula?

First solve the moles of oxgen present in the compound

mol O = 6.93 g O (1 mol O / 16 g O)

mol O = 0.43 mol H

then solve the moles of hydrogen present

mol H = (7.36 - 6.93) g H (1 mol H / 1 g H)

mol H = 0.43 mol H

so the O and H are in the same mole content so the molecular formula would be OH, but the molar mass will not satisfy. so the answer would be

H2O2