Question

What is the empirical formula of a molecule containing 65.5% carbon, 5.5% hydrogen, and 29.0% oxygen?

Answer 1

Answer:

The empirical formula is C3H3O

Explanation:

Step 1: Data given

Suppose the mass of the molecule = 100 grams

The molecule contains:

65.5 % Carbon = 65.5 grams

5.5 % Hydrogen = 5.5 grams

29.0% Oxygen = 29.0 grams

Molar mass of C = 12 g/mol

Molar mass of H = 1.01 g/mol

Molar mass of O = 16 g/mol

Step 2: Calculate moles

Moles = mass / molar mass

Moles C = 65.5 grams / 12 g/mol = 5.46 moles

Moles H = 5.5 / 1.01 g/mol = 5.45 moles

Moles O = 29.0 grams / 16 g/mol = 1.8125 moles

Step 3: Calculate mol ratio

We divide by the smallest amount of moles

C: 5.46 / 1.8125 = 3

H = 5.45 / 1.8125 = 3

O = 1.8125/1.8125 = 1

The empirical formula is C3H3O