1. Determine the empirical formula:
* Assume a 100 g sample: This makes the percentages directly equal to grams.
* Convert grams to moles:
* Carbon: 65.45 g / 12.01 g/mol = 5.45 mol
* Hydrogen: 5.45 g / 1.01 g/mol = 5.40 mol
* Oxygen: 29.09 g / 16.00 g/mol = 1.82 mol
* Divide by the smallest number of moles:
* Carbon: 5.45 mol / 1.82 mol = 3
* Hydrogen: 5.40 mol / 1.82 mol = 3
* Oxygen: 1.82 mol / 1.82 mol = 1
* The empirical formula is C3H3O
2. Determine the molecular formula:
* Calculate the empirical formula mass: (3 * 12.01) + (3 * 1.01) + (1 * 16.00) = 55.06 g/mol
* Find the ratio of the molar mass to the empirical formula mass: 110.1 g/mol / 55.06 g/mol = 2
* Multiply the subscripts in the empirical formula by the ratio: C3H3O * 2 = C6H6O2
Therefore, the molecular formula of hydroquinone is C6H6O2.
