To find the empirical formula of CH₄O, we need to determine the simplest whole number ratio of the elements present. We can assume we have 1 mole of the compound, so we have:

1 mole of C

4 moles of H

1 mole of O

Next, we need to find the relative number of moles of each element by dividing the number of moles of each element by the smallest number of moles. In this case, the smallest number of moles is 1, so the relative number of moles are:

1 mole of C

4 moles of H

1 mole of O

Finally, we can convert the relative number of moles to a whole number ratio by dividing each number by the greatest common factor. In this case, the greatest common factor is 1, so the whole number ratio is:

1 mole of C

4 moles of H

1 mole of O

Therefore, the empirical formula of CH₄O is CH₄O.