<p>name:______date:______pd:___</p><p>The Chemistry Mole: Molar Mass, % Composition, Empirical & Molecular Formulas Funsheet</p><p>Directions: Complete the following problems. SHOW ALL WORK. Remember to keep track of significant figures and units!</p><p>1. You want to react a 0.750 mole sample of potassium with bromine in the laboratory. Assume you need one atom of bromine for every atom of potassium to complete the reaction. How many grams of bromine are needed?</p><p>2. How many moles of helium are in 2.02 x 1024 atoms of helium?</p><p>3. A small fleck of gold has a mass of 8.24 x 10-6 grams. How many atoms of gold does it contain?</p><p>4. What mass of silver contains the same number of atoms as 9.0 grams of aluminum?</p><p>5. What is the molar mass of sucrose, C12H22O11? 6. Benzaldehyde (C6H5CHO) is a colorless liquid has a characteristic pleasant almond-like odor. It is used in various fragrances for soap and toiletries. Calculate its molar mass.</p><p>7. 2.50 moles of Na2Al2(SO4)4 would weigh how much in grams?</p><p>8. 300. grams of Pb3(AsO4)2 would equal how many moles?</p><p>9. Calculate the percent composition of each element in (NH4)2C2O4.</p><p>10. What is the percent composition of Bi2O3? 11. Aluminum sulfate is an industrial chemical used in the purification of drinking water. Calculate its percent composition.</p><p>12. Determine the empirical formulas of these three iron oxide compounds: a. 77.7% Fe, 22.3% O</p><p> b. 72.4% Fe, 27.6% O</p><p> c. 70.0% Fe, 30.0% O</p><p>13. In an experiment, a chemist reacts 0.0134 grams of iron, 0.00769 grams sulfur, and 0.0115 grams of oxygen. What is the empirical formula of the compound she produces? 14. A compound’s empirical formula is CH2O. Its molecular mass is 120.12 grams. Calculate its molecular formula.</p><p>15. A compound contains 49.5% iron and 50.5% fluorine. It has a molecular mass of 338.5 grams. Determine its molecular formula.</p><p>16. Determine the molecular formula for a compound containing 0.608 grams N and 1.388 grams O. Its molecular mass is 92.0 grams.</p>