Sodium metal reacts with water form hydrogen gas by the following unbalanced chemical equation
Na(s) + H₂O(l) → NaOH(aq) + H₂(g)
If 20 g of sodium are reacted with excess water at a temperature of 30°C and a pressure of 0.8 atm, what volume of H₂ is produced?

Question

Quizplus · Accepted Answer

First, balance the equation: 2Na + 2H₂O → 2NaOH + H₂. Moles of Na = 20 g / 23 g/mol = 0.87 mol. From the balanced equation, 2 moles of Na produce 1 mole of H₂, so 0.87 moles of Na produce 0.435 moles of H₂. Using the ideal gas law (PV = nRT) with R = 0.0821 L·atm/mol·K and T = 303 K, V = nRT/P = (0.435 mol)(0.0821 L·atm/mol·K)(303 K) / 0.8 atm = 13.5 L.

Sodium Metal Reacts with Water Form Hydrogen Gas by the Following