Hi, I was wondering when calculating the empirical formula from percent you will also have an element with no subscript. In other words in an empirical formula you can't have C3H8 right, it would have to be something like CH4. If anyone knows the answer can they please help me.

An element can be without a subscript. For example, H2O is an empirical formula. An empirical formula just means that the elements in the molecule are represented in their lowest whole number ratios. So the chemical formula for hydrogen peroxide is H2O2, but the empirical formula is HO.

C3H8 is an empirical formula; you cant divide the 3 and 8 by anything and get whole numbers