Final answer:
120 g of Na would produce 5.22 g of H₂, calculated using the molar mass of Na (23 g/mol) and the stoichiometry of the balanced chemical reaction.
Step-by-step explanation:
The student has asked how many grams of hydrogen are produced if 120 g of Na are available, using the balanced equation 2Na + 2H₂O → 2NaOH + H₂. First, we calculate the number of moles of sodium (Na) by using its molar mass, which is approximately 23 g/mol. With 120 g of sodium, we have:
Number of moles of Na = 120 g / 23 g/mol = 5.22 moles
According to the balanced equation, 2 moles of Na produce 1 mole of H₂. Therefore, 5.22 moles of Na will produce:
Number of moles of H₂ = 5.22 moles of Na * (1 mole H₂ / 2 moles Na) = 2.61 moles H₂
The molar mass of H₂ (hydrogen gas) is approximately 2 g/mol. So, the mass of hydrogen produced is:
Mass of H₂ = 2.61 moles * 2 g/mol = 5.22 g of H₂