Worksheet: Empirical and Molecular Formulas
On a separate piece of paper, answer the following questions, showing all of your work (formulas, calculations and final answers with units). Add a concluding statement for each answer.
1. Calculate the empirical formula of a compound containing 44.9% potassium, 18.4% sulphur, and 36.7% oxygen. Arrange the elements by this order: K, S, O
2. The composition of nicotine is 74.0% C, 8.7% H, and 17.3% N. The molecular mass of nicotine is 162 g/mol. What is its molecular formula? (Hint: Arrange the atomic symbols in alphabetical order. In this question, it would be C, H, N).
3. One compound of mercury with a formula weight of 519 g/mol contains 77.26% Hg, 9.25% C, and 1.17% H, and the remainder is oxygen. Calculate its empirical and molecular formulas, arranging the atomic symbols in the order Hg, C, H, and O.
4. One of the most deadly poisons, strychnine, has a formula weight of 334 g/mol and the composition 75.42% C, 6.63% H, 8.38% N; the rest is oxygen. Calculate the empirical and molecular formulas of strychnine, arranging the atomic symbols in alphabetical order.
Answers:
1) K2SO4 2) C10H14N2 3) Hg2C4H3O4 / Hg2C4H3O4 4) C21H22N2O2 / C21H22N2O2
Worksheet: Empirical and Molecular Formulas
On a separate piece of paper, answer the following questions, showing all of your work (formulas, calculations and final answers with units). Add a concluding statement for each answer.
5. Calculate the empirical formula of a compound containing 44.9% potassium, 18.4% sulphur, and 36.7% oxygen. Arrange the elements by this order: K, S, O
6. The composition of nicotine is 74.0% C, 8.7% H, and 17.3% N. The molecular mass of nicotine is 162 g/mol. What is its molecular formula? (Hint: Arrange the atomic symbols in alphabetical order. In this question, it would be C, H, N).
7. One compound of mercury with a formula weight of 519 g/mol contains 77.26% Hg, 9.25% C, and 1.17% H, and the remainder is oxygen. Calculate its empirical and molecular formulas, arranging the atomic symbols in the order Hg, C, H, and O.
8. One of the most deadly poisons, strychnine, has a formula weight of 334 g/mol and the composition 75.42% C, 6.63% H, 8.38% N; the rest is oxygen. Calculate the empirical and molecular formulas of strychnine, arranging the atomic symbols in alphabetical order.
Answers:
1) K2SO4 2) C10H14N2 3) Hg2C4H3O4 / Hg2C4H3O4 4) C21H22N2O2 / C21H22N2O2