How many grams of Al are required to produce 17.5 g of hydrogen

Answer 1

Assuming you are talking about the reaction of Al with HCl, for example, then you would proceed as follows:

Write a balanced equation:

2Al + 6HCl ==> 2AlCl₃ + 3H₂

Next, use dimensional analysis and the stoichiometry of the balanced equation:

17.5 g H₂ x 1 mol H₂/2 g x 2 mol Al/3 mol H₂ x 27.0 g Al/mol Al = 158 g Al needed