Question

According to the equation 2Na + 2H2O mc012-1.jpg 2NaOH+H2, what mass of Na is required to yield 22.4 L of H2 at STP? (The atomic mass of Na is 22.99 u.)

Answer 1

Use the ideal gas law, PV = nRT

https://en.wikipedia.org/wiki/Ideal_gas_law
first paragraph

to find moles of H2 you need

Then use the reaction equation and the moles of H2 to find out the amount of moles of Na you need

then use the formula moles = grams/molecular mass to find grams of sodium

Answer 2

(22.4 L H2) / (22.4 L/mol) x (2 mol Na / 1 mol H2) x (22.98977 g Na/mol) =
46.0 g Na