Final answer:
Approximately 214.3 grams of aluminum (Al) are needed to react with excess hydrochloric acid (HCl) to produce 24.0 grams of hydrogen gas (H2) according to the given chemical equation.
Step-by-step explanation:
Calculating the Required Grams of Aluminum
The student has asked how many grams of aluminum (Al) are needed to react with excess hydrochloric acid (HCl) in order to produce 24.0 grams of hydrogen gas (H2) according to the chemical equation 2Al + 6 HCl → 2 AlCl3 + 3 H2.
First, we need to convert the mass of H2 to moles using the molar mass of hydrogen (approximately 2.016 g/mol). With 24 grams of H2, we get 24 / 2.016 = 11.905 moles of H2.
According to the balanced equation, for every 3 moles of H2 produced, 2 moles of Al are consumed.
Therefore, 11.905 moles of H2 correspond to 7.937 moles of Al (11.905 × (2/3)).
The molar mass of Al is approximately 26.98 g/mol, so we multiply the number of moles of Al by this molar mass to find the mass required: 7.937 moles × 26.98 g/mol = 214.320 grams of Al.
Therefore, approximately 214.3 grams of Al are needed to produce 24.0 grams of H2.