Empirical and Molecular Formulas Name:______________________________ Show your work and include units for credit 1. An unknown compound was found to have a percent composition as follows: 47.0 % potassium, 14.5 % carbon, and 38.5 % oxygen. What is its empirical formula? If the true molar mass of the compound is 166.22 g/mol, what is its molecular formula? 2. A component of protein called serine has an approximate molar mass of 100 g/mole. If the percent composition is as follows, what is the empirical and molecular formula of serine? C = 34.95 % H= 6.844 % O = 46.56 % N= 13.59 % 3. A compound contains 63.11 % C, 12.36 % H, and 24.53 % N. What is its empirical formula? If the experimental molar mass is 114.2 g/mol, what is the molecular formula? 4. A certain carbohydrate compound (containing only C, H and 0) is 40.0% C, 6.72% H, and 53.3% O by mass. The experimentally determined molecular mass is 180 g/mol. What is the empirical and molecular formula for this carbohydrate? 5. A certain hydrocarbon compound (containing only C and H) is 83.6% C and 16.4% H by mass. The experimentally determined molecular mass is 86.2 amu. What is the empirical and molecular formula for this hydrocarbon? 6. Ricinine contains 8 carbon atoms, 8 hydrogen atoms, 2 nitrogen atoms, and 2 oxygen atoms. a. What is the molecular formula of Ricinine? b. What is the empirical formula of Ricinine? c. What is the molar mass of Ricinine? 7. Borazine contains 3 boron atoms, 6 hydrogen atoms, and 3 nitrogen atoms. a. What is the molecular formula of Borazine? b. What is the empirical formula of Borazine? c. What is the molar mass of Borazine? 8. The composition of silver oxalate is 71.02% silver, 7.91% carbon, and 21.07% oxygen. If the molar mass of silver oxalate is 303.8 g/mol. Determine the empirical and molecular formula. 9. A compound of phosphorus and sulfur contains 27.87% phosphorus and 72.13% sulfur. The molar mass of the compound is 222.3 g/mol. Determine the empirical and molecular formula. 10. Triethylenemelamine is used in the plastics industry and as an anti-cancer drug. Its analysis is 52.93% carbon, 5.92% hydrogen, and 41.15% nitrogen. The molar mass is 204.2 g/mol. Determine the empirical and molecular formula. .