Sign in

GCSE Science | Empirical Formula

Last updated on 

Work out the empirical formula

  1. 75% carbon, 25% hydrogen
  2. 52.7% potassium, 47. 3% chlorine
  3. 22. 1% aluminum, 25.4% phosphorus, 52.5% oxygen
  4. 13% magnesium, 87% bromine

Work out the molecular formula

  1. The empirical formula of a compound is NO2. Its molecular mass is 92 g/mol. What is the molecular formula?
  2. The empirical formula of a compound is CH2. Its molecular mass is 70 g/mol. What is its molecular formula?
  3. A compound is found to be 40% carbon, 6.7 % hydrogen and 53.5 % oxygen. Its molecular mass is 60. g/mol. What is its molecular formula?
  4. Caffeine has an elemental analysis of 49.48% Carbon, 5.19 % hydrogen, 16.47% oxygen, and 28.85% nitrogen. It has a molar mass of 194.19 g/mol. What is the molecular formula for caffeine?