[whatisbarium2sodium]

i cant figure out how to determine the molecular formula when given the relative abundance of each element and the mass. i cant make the connection on where to start. im more concerned on understanding the concept then getting the answer so.. any explanations would be greatly appreciated :]

a compound that is composed of carbon, hydrogen, and oxygen contains 70.6% C, 5.9% H, and 23.5% O by mass. The molecular weight of the compound is 136 amu. What is the molecular formula?

i started with taking a hypothetical 100g and finding how many moles of each substance i have.. do i find the emperical formula next? then take the molar mass of the emperical formula and divide it by the mass given of 136 g to find the molecular formula?

[Schrödinger]

In order to find the empirical formula, you need to find the relative amounts of each element. So, divide the percentages the lowest factor so that you get those relative numbers as integers.

Once you have the empirical formula, see how much one formula unit of it weighs and for it to weigh 136 amu, what needs to be done.

[fledarmus]

i started with taking a hypothetical 100g and finding how many moles of each substance i have.. do i find the emperical formula next? then take the molar mass of the emperical formula and divide it by the mass given of 136 g to find the molecular formula?

The description certainly sounds accurate. How did it work out when you went through the numbers?

[AWK]

When you have a molecular mass and percentage just calculate masses of elements in molecular mass (using percentages) and convert them to numbers of atoms