J.R. S. answered 10/24/23
Ph.D. University Professor with 10+ years Tutoring Experience
First, let's write a correctly balanced equation for the reaction that is taking place:
Zn(s) + 2HCl(aq) ==> ZnCl2(aq) + H2(g) ... balanced equation
Next, we will find the MOLES of Zn that are present:
Atomic mass Zn = 65.39 g / mole
9.35 g of ore x 25.0% Zn = 2.338 g of Zn
2.338 g Zn x 1 mol Zn / 65.39 g = 0.0357 moles Zn in the ore sample
Next, we will use the stoichiometry (mole ratio) of the balanced equation to find the MOLES of HCl needed:
0.0357 mols Zn x 2 mols HCl / 1 mol Zn = 0.0714 mols HCl needed
Finally, using the given concentration of HCl (6.5 M), we will convert mols HCl to mls HCl:
6.5 M HCl mean 6.5 moles HCl / L
0.0714 mols HCl x 1 L / 6.5 mols = 0.01098 L
0.01098 L x 1000 mls / L = 10.98 mls = 11.0 mls (to 3 sig.figs.) = Answer