Answer:
Taking into account the reaction stoichiometry, the correct answer is option B): 9 grams of aluminum are necessary to produce 0.50 mol of hydrogen gas at 25°C and 1.0 atm.
Step-by-step explanation:
The balanced reaccion is:
6 HCl + 2 Al → 2 AlCl₃ + 3 H₂
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
HCl: 6 moles
Al: 2 moles
AlCl₃: 2 moles
H₂: 3 moles
The atomic mass of aluminum is 27 g/mole. Then, by reaction stoichiometry, the following mass quantity of aluminum participates in the reaction:
Then you can apply the following rule of three: if by reaction stoichiometry 3 moles of H₂ are formed from 54 grams of Al, 0.50 moles of H₂ are formed from how much mass of Al?
mass of Al= 9 grams
In summary, the correct answer is option B): 9 grams of aluminum are necessary to produce 0.50 mol of hydrogen gas at 25°C and 1.0 atm