Question

which would be considered a molecular formula, but not an empirical formula?
n₂h₄
h₂o
cc - 12
nh₂

Explanation:

An empirical formula gives the simplest whole - number ratio of atoms in a compound. A molecular formula is either the same as or a multiple of the empirical formula. For $N_2H_4$, the simplest ratio of $N$ to $H$ is $1:2$ (empirical formula $NH_2$), so $N_2H_4$ is a molecular formula but not an empirical formula. $H_2O$ is both a molecular and empirical formula as the ratio of $H$ to $O$ is already in the simplest whole - number ratio. $CC - 12$ is not a chemical formula. $NH_2$ is an empirical formula.

Answer:

A. $N_2H_4$