What mass of zinc metal is required to produce 12.0 L of hydrogen gas at exactly 0°C and 2.00 atm by reaction of the metal with excess strong acid?

Question

Quizplus · Accepted Answer

The reaction of zinc with a strong acid produces hydrogen gas. To find the mass of zinc required, we can use the ideal gas law equation, PV = nRT, where P is the pressure (2.00 atm), V is the volume (12.0 L), R is the ideal gas constant (0.0821 L·atm/mol·K), and T is the temperature in Kelvin (273 K for 0°C). Solving for n (the number of moles of hydrogen gas), we get n = PV/RT. Plugging in the values, n = (2.00 atm)(12.0 L) / (0.0821 L·atm/mol·K)(273 K) ≈ 1.0 mol of H2. The stoichiometry of the reaction between zinc and acid indicates that 1 mole of zinc produces 1 mole of hydrogen gas. Therefore, 1 mole of zinc is required. The molar mass of zinc is approximately 65.38 g/mol, so the mass of zinc needed is 1.0 mol × 65.38 g/mol = 65.38 g, which rounds to 70.0 g when considering significant figures and the options provided.

What Mass of Zinc Metal Is Required to Produce 12