posted by Cecille .
A 6.0g of methane decomposes into 4.5g of Carbon and 1.5g of Heydrogen. Determine the empirical formula of methane.
I would find the percent C and H.
(4.5/6.0)*100 = 75% C
(1.5/6.0)*100 = 25% H
Now take a 100 gram sample which will give you
75g C and 25g H. Now convert to moles.
moles C = 75/12 = 6.25
moles H = 25/1 = 25
Now find the smallest whole-number ratio between the two elements; the easy way to do this is to divide both values for moles by the smaller number, then divide the other value by the same small number. This gives you 1.00 for the first one and usually a whole number for the other. That will be the empirical formula.