The balanced chemical reaction is:
Zn (s) + 2 HCl (aq) ---> ZnCl2 (aq) + H2 (g)
We are given the amount of the hydrochloric acid to be used in the reaction. This will be used for the calculations.
3.5 mol/L HCl (8.2 L) (1 mol Zn / 2 mol HCl) (65.38 g / 1 mol) = 938.20 g Zn