Zn(s)+2HCl(aq) ->ZnCl2(aq)+Hx(g)

Question

How many millilters of 2.50M HCl(aq) are required to react with 3.95 of Zn(s)?

Answer 1

mols Zn = grams/atomic mass = ?
mols HCl = twice that (from the coefficients in the balanced equation).
M HCl = mols HCl/L HCl. You know M and mols, solve for L HCl and convert to mL.