Small quantities of hydrogen can be prepared by the addition of hydrochloric acid to zinc. A sample of 195 mL of hydrogen was collected over water at 25$\degree$C and 753 torr. What mass of hydrogen was collected? (P_water = 24 torr at 25$\degree$C)

Question

Quizplus · Accepted Answer

The pressure of hydrogen is 753 torr - 24 torr = 729 torr. Using the ideal gas law, PV = nRT, convert the volume to liters (0.195 L), pressure to atm (729/760 atm), and use R = 0.0821 L·atm/mol·K and T = 298 K to find moles of H2. Then, multiply by the molar mass of H2 (2.02 g/mol) to find the mass.

Small Quantities of Hydrogen Can Be Prepared by the Addition °\degree°

Small Quantities of Hydrogen Can Be Prepared by the Addition $\degree$