Chapter 4, Problem 4.61PAE

4.59 Aluminum dissolves in HCI according to the equation written below, whereas copper does not react with HCl.

$\text{2 Al}\left(\text{s}\right)+\text{ 6 HCl}\left(\text{aq}\right)\to {\text{ 2 AlCl}}_{\text{3}}\left(\text{aq}\right)+{\text{ 3 H}}_{\text{2}}\left(\text{g}\right)$

A 35.0-g sample of a copper—aluminum alloy is dropped into 750 mL of 3.00 M HCl, and the reaction above proceeds as far as possible. If the ahoy contains 77.1% Al by mass, what mass of hydrogen gas would be produced?