The chemical formula is different from the empirical formula in A) H2O2
B) CO2
C) CO.
OD) H20.

A) H2O2

Explanation:

Hydrogen peroxide is written as H2O2, which is the chemical formula of the compound, but this can be simplified. Since both H and O have the subscript of 2, they can be simplified to 1, so the empirical formula for H2O2 would be just H and O together ( won't let me say the empirical form because it has the same spelling as a swear word). Thus, the empirical formula and chemical formula are different.

In the case of the other options, they are all in their simplest form and cannot be simplified further, so they are already in their empirical form, so both the chemical form and empirical form are the same.