# Gas Stoichiometry Essay

278 Words2 Pages
5.04H: Gas Stoichiometry Lab Worksheet Name: _________________________ Data and Observations: Present all relevant data in a data table below. Include an observations section for any observations that you made during the lab. (5 points) Data Table| Mass of magnesium strip (grams)|0.0304g| Volume of gas collected (mL)|10ml| Barometric pressure (atm)|1.1| Room Temperature (°C)|21 | Vapor pressure of the water (torr)|18.7| Calculations: 1. Write the balanced equation for the reaction conducted in this lab, including appropriate phase symbols. (2 points) Mg(s) + 2 HCl(aq) → H2(g) + MgCl2(aq) 2. Determine the partial pressure of the hydrogen gas collected in the gas collection tube. (3 points) partial pressure H2 = total pressure - vapor pressure of water = 746mmHg - 19.8mmHg = 726mmHg 3. Calculate the moles of hydrogen gas collected. (4 points) n = 125 4. If magnesium was the limiting reactant in this lab, calculate the theoretical yield of the gaseous product. Show all steps of your calculation. (4 points) Moles of Mg: (0.0281 g)(1 mole / 24.305 g) = 1.156 x 10^-3 moles 5. Determine the percent yield of this reaction, showing all steps of your calculation. (3 points) heoretical yield of H2 gas: (1.156 x 10^-3 moles)(1 mole H2/ 1 mole Mg) = 1.156 x 10^-3 moles Theoretical mass: (1.156 x 10^-3 moles)(2.02 g/mole) = 2.335 x 10^-3 g Using ideal gas law: P = (1.1 atm)(760 torr / 1 atm) - 19.8 torr = 816.2 torr V = 0.026 L T = 295 K Solve for n: n = PV/(RT) n = (816.2 torr)(0.026