Zinc metal reacts with hydrochloric acid according to the following equation: Zn + 2HCl yields ZnCl2 + H2. How many grams of hydrogen gas can be obtained if 50.0 g of zinc react completely?
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To calculate the amount of hydrogen gas produced when 50.0 g of zinc reacts completely with hydrochloric acid, we need to use stoichiometry.
1. Start by balancing the chemical equation:
Zn + 2HCl -> ZnCl2 + H2
2. Determine the molar mass of zinc (Zn) from the periodic table:
Molar mass of Zn = 65.38 g/mol
3. Convert the given mass of zinc (50.0 g) to moles using its molar mass:
Moles of Zn = (50.0 g) / (65.38 g/mol)
4. Since the balanced equation tells us that 1 mole of zinc produces 1 mole of hydrogen gas (H2), the moles of hydrogen gas produced will be equal to the moles of zinc.
5. Determine the molar mass of hydrogen gas (H2) from the periodic table:
Molar mass of H2 = 2.02 g/mol
6. Convert the moles of hydrogen gas to grams using its molar mass:
Grams of H2 = (moles of H2) * (molar mass of H2)
So, to find the grams of hydrogen gas formed, you can substitute the moles of zinc into the equation directly without further calculations.
Therefore, 50.0 g of zinc will produce 50.0 g of hydrogen gas when reacted completely.
mols Zn = grams/molar mass
Convert mols Zn to mols H2 susing the coefficients in the balanced equation.
Now convert mols H2 to g. g = mols x molar mass.