# How do we determine the molecular formula of a carbonyl species, C_nH_(2n)O?

Jul 16, 2017

Without a molecular weight determination you are a shot bird..........

#### Explanation:

Formaldehyde, acetaldehyde, acetone, all the MONOFUNCTIONAL ketones and aldehydes have a formula of ${C}_{n} {H}_{2 n} O$. For formaldehyde, $n = 1$, but $n$ could equal $2 , 3 , 4. \ldots \ldots . .$, and generate the same empirical formula.....

TO get the molecular formula, you need a molecular weight determination. Got one?

A useful idea to develop in this context is the so-called degree of unsaturation. You have the one degree of unsaturation for this problem.