Answer:
The molecular formula is C6H6O2
Explanation:
Step 1: Data given
Suppose the mass of the compound = 100 grams
The compound has:
65.45 % C = 65.45 grams
5.492 % H = 5.49 grams
29.06 % O = 29.06 grams
Molar mass C = 12.01 g/mol
Molar mass H = 1.01 g/mol
Molar mass O = 16.00 g/mol
Molar mass = 110 g/mol
Step 2: Calculate moles
Moles = mass / molar mass
Moles C = 65.45 grams / 12.01 g/mol
Moles C = 5.450 moles
Moles H = 5.49 grams / 1.01 g/mol
Moles H = 5.44 moles
Moles O = 29.06 grams / 16.00 g/mol
Moles O = 1.816 moles
Step 3: Calculate mol ratio
We divide by the smallest amount of moles
Moles C = 5.450 moles / 1.816 = 3
Moles H = 5.44 moles / 1.816 = 3
Moles O = 1.816/1.816 = 1
The empirical formula is C3H3O
The molar mass of this formula is 55 g/mol
We have to multiply the empirical formula by n
n = 110/55 = 2
2*(C3H3O) = C6H6O2
The molecular formula is C6H6O2
