posted by Robert .
How many milliliters of 6.50 M HCl(aq) are required to react with 5.95 g of an ore containing 35.0% Zn(s) by mass?
Zn + 2HCl ==> Zn^2+ ....
g Zn = 5.95*0.35 = ?
mols Zn = ?g Zn/atomic mass Zn
Convert mols Zn to mols HCl using the coefficients.
M HCl = mols HCl/L HCl. You know M and mols, solve for L and convert to mL.