How can empirical and molecular formulas be the same?

1 Answer
May 2, 2016

The molecular formula is always a multiple of the empirical formula.

Explanation:

From the above, #"Molecular formula"=("Empirical formula")xxn#.

Of course, the multiple, #n#, may be ONE. Non-molecular compounds, typically ionic compounds, have common empirical and molecular formulae (of course ionic species are non-molecular).

There are even some molecular species whose empirical formulae would be the same as the molecular formulae. The ones I can think off hand are #CH_4#, #NO#, #NO_2#, #N_2O#, #N_2O_5#, #CO_2#, #CO#, and #H_2O#. There are possibly lots of other examples.