To solve this problem, we need to use stoichiometry and the ideal gas law. Here are the steps:
1. Write the balanced chemical equation: 2Na + 2H2O → 2NaOH + H2
2. Find the moles of Na from its mass:
moles of Na = 15.0 g / 23.0 g/mol = 0.652 moles of Na
3. Use the mole ratio between Na and H2 to find the moles of H2:
moles of H2 = 0.652 moles of Na × (1 mole of H2 / 2 moles of Na) = 0.326 moles of H2
4. Use the ideal gas law to find the volume of H2 at STP (Standard Temperature and Pressure):
PV = nRT, where P = 1 atm, V = ?, n = 0.326 moles, R = 0.0821 L·atm/(mol·K), T = 273 K.
V = nRT/P = (0.326 moles) × (0.0821 L·atm/(mol·K)) × (273 K)/(1 atm) ≈ 7.3 L
Therefore, the answer is (c) 7.30 L.
What volume of hydrogen gas at STP is produced by the complete reaction of 15.0 g of sodium according to the following equation:
2Na + 2H2O -----> 2NaOH + H2?
a
14.6 L
b
10.2 L
c
7.30 L
d
18.3 L
1 answer