Question

How many liters of 18.5 molar HCl stock solution will be needed to make 25.0 liters of 1.5 molar HCl solution? Show the work used to solve this problem.

Answer 1

1) Find the number of moles that the final solution must contain

M = n / liters of solution => n = M*liters of solution

n = 1.5 mol/liter * 25.0 liter = 37.5 moles

2) Find how many liters of the stock solution contain 37.5 moles of HCL

M = n / liters of sulution => liters of solution = n / M = 37.5 mol / 18.5 mol/liter

liter of solution = 2.03 liter

Answer: 2.03 liter