Question

Name: Date: Instructor's Initials: Lab Section: The Ideal Gas Constant PreLab: sing the Balanced Equation (1), determine how many moles of hydrogen should be produced by 0.036 grams of Mg metal using an excess of HCI. If the average temperature of the water was 21.5 °C, what pressure inside the Graduated cylinder is contributed by the water vapor? (See Table 1). 3. If the atmospheric pressure in the lab was 754 mmHg on that day, what would be the pressure of the hydrogen gas at 21.5°C? (Use Equation (3a) and the water vapor pressure at 21.5 °C). 4. If the gas produced in the above reaction occupied a volume of 38.2 ml, what would be the value for R using the values from above (use pressure units of mmHg, NOT atm)? 113

Answer 1

"Answer My + HCl → H2 (9) + My Cly The Balanced equation is Mg (3) + 2HC) (as) the (9) + Mgch (12) 1 mole mg produce, From the balanced equation 1 mole of Ma gas. 1 mole ng 1 mole h a Given 0.036g of Mg we know that number of moles= weight molar mass of Mg = 249{mos molar mais - no 0.0369 249/mol - - 0.0015 mol . mg moles = 0.001s mol → 1 mole ng 1 mole ha .: 0.0015 mol mg 0.0015 mol Hy 0.0015 mol of y gas produced = 1.5X103 mo)