Question

A sample of a white powder was analyzed in the laboratory and found to be composed of 40% carbon, 6.67% hydrogen, and 53.33% oxygen by mass. Determine the empirical formula of the compound.

Answer 1

To determine the empirical formula of the compound, we will follow these steps:1. Assume that we have 100 grams of the compound. This means that we have 40 grams of carbon, 6.67 grams of hydrogen, and 53.33 grams of oxygen.2. Convert the mass of each element to moles by dividing by their respective molar masses.3. Divide each mole value by the smallest mole value to get the mole ratio.4. Round the mole ratio to the nearest whole number to get the empirical formula.Step 1: Assume 100 grams of the compound- Carbon: 40 grams- Hydrogen: 6.67 grams- Oxygen: 53.33 gramsStep 2: Convert mass to moles- Carbon: 40 g / 12.01 g/mol  molar mass of C  = 3.33 mol- Hydrogen: 6.67 g / 1.01 g/mol  molar mass of H  = 6.60 mol- Oxygen: 53.33 g / 16.00 g/mol  molar mass of O  = 3.33 molStep 3: Divide each mole value by the smallest mole value- Carbon: 3.33 mol / 3.33 mol = 1- Hydrogen: 6.60 mol / 3.33 mol = 1.98  2- Oxygen: 3.33 mol / 3.33 mol = 1Step 4: Round the mole ratio to the nearest whole number- Carbon: 1- Hydrogen: 2- Oxygen: 1The empirical formula of the compound is CH2O.