There isn't much more left to say. You can see that
chenbeier: has done some work for you, and given you the molecular formulas. Your empirical formula is just a shorthand reducing the numbers of atoms to the least common denominator. Glucose is nothing like formaldehyde structurally -- it isn't even 6 formaldehydes strung together, some groups are different along the molecule.
but why?
Kindly don't behave this way on our forum. No one older than 5 years old is permitted, in this world, to just ask "But why?" Use the definition of empirical formula to see for yourself how the empirical formula should be used.
Kindly,
stormaktstid:, I'd like to welcome you and all the new chemists to the Chemical Forums. But I'd like to ask you to trouble yourself to read our
Forum Rules{click}. You already accepted them when you signed up for our forum, and they apply to you, whether you agree with them or not, or even if you're unaware of them.
Our rules specify that we want to see your work, and then, we want to give you hints, so that you learn for yourself. It doesn't matter if you're a new student, or a dedicated amateur, we need to know what you know, and what you think, so we know what level you're at, so we can give useful hints, so your knowledge can grow.