to solve this problem. use the formula
m1 v1 = m2 v2
where m1 is the molarity of the stock soln
v1 is the volume of the stock soln
m2 is the molarity of the new soln
v2 is the volume of the new soln
m1 v1 = m2 v2
13.5(v2) = (10.5)(1.8)
v2 = (10.5)(1.8) / 13.5
v2 =1.4 L is needed from the 13.5 M HCl stock soln
