Question

How many liters of 0.85 M HCl solution would react completely with 3.5 moles Ca(OH)2? Ca(OH)2(s) + 2 HCl(aq) yields CaCl2(aq) + 2 H2O(l)

Answer 1

Ca(OH)2(s) + 2 HCl(aq) -----> CaCl2(aq) + 2 H2O(l)
3.5 moles        2*3.5 moles

we need  2*3.5 moles HCl= 7.0 mol HCl
7 mol HCl *1L solution HCl/0.85 mpl HCl=8.2 L 0.85 M HCl solution
8.2 L 0.85 M HCl solution