how many grams of hydrogen are produced if you have 120 grams of sodium?
2Na+2H2O->2NaOH+H2
To determine the number of grams of hydrogen produced when you have 120 grams of sodium, you need to use stoichiometry, which relates the number of moles between different substances in a chemical equation.
In this balanced equation:
2Na + 2H2O → 2NaOH + H2
We can see that for every 2 moles of Na, 1 mole of H2 is produced.
To calculate the number of moles of Na present in 120 grams, you need to know the molar mass of sodium. The molar mass of sodium (Na) is approximately 22.99 g/mol.
Number of moles of Na = Mass of Na / Molar mass of Na
Number of moles of Na = 120 g / 22.99 g/mol
Number of moles of Na ≈ 5.22 mol
Using the stoichiometry of the balanced equation, we know that:
2 moles of Na = 1 mole of H2
Therefore, the number of moles of H2 produced is half the number of moles of Na (since the ratio between the two is 2:1):
Number of moles of H2 = 5.22 mol / 2
Number of moles of H2 ≈ 2.61 mol
Finally, to convert the moles of H2 to grams, you need to use the molar mass of hydrogen. The molar mass of hydrogen (H2) is approximately 2.02 g/mol.
Mass of H2 = Number of moles of H2 × Molar mass of H2
Mass of H2 = 2.61 mol × 2.02 g/mol
Mass of H2 ≈ 5.27 g
Therefore, approximately 5.27 grams of hydrogen are produced when you have 120 grams of sodium.
Just follow the steps in the example stoichiometry problem.
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