a compound is analysed and found to have the atomic composition of C 54.5454% H 9.0909 % o 36.3636%. at a temp. of 120C and a pressure of 608 mm the density is 2.183 g/L. what is its molecular formula.
Take a 100 g sample, then you will have those percentages in grams.
Convert to mols.
Find the ratio of the mols to each other with the smallest number being 1.00. The easy way to do that is to divide the smallest number by itself. Round to whole numbers but be careful not to round too much; i.e., not more than about 0.2 or so. You can use PM = dRT to solve for molar mass.