Answer:
C₆H₆O
Explanation:
The given values are the percentage in mass of each element. Empirical formula is the simplest ratio of atoms presents in a molecule. Thus, the first we need to do is convert this percentage to mass using molar mass of each element:
Moles C:
76.57C * (1mol / 12g) = 6.38 moles C
Moles H:
6.43 * (1mol / 1g) = 6.43 moles H
Moles O:
17.0% * (1mol / 16g) = 1.06 moles O
Dividing each number of moles in the moles of O (The minimum number of moles. Used to obtain "The simplest ratio..."):
C = 6.38 moles C / 1.06 moles O = 6
H = 6.43 moles H / 1.06 moles O = 6
O = 1.06 moles O / 1.06 moles O = 1
That means empirical formula of phenol is:
C₆H₆O
