Answer to Question #97842 in Chemistry for Isabella Burry

Question

You need 50mL of an HCl solution that is 0.02N. You have on hand a 0.5N solution. How would you prepare this solution to give the desired volume and concentration?

Answer 1

For hydrochloric acid:

C₁(HCl) = 0.5N = 0.5M

C₂(HCl) = 0.02N = 0.02M

n(HCl) = C₂(HCl) × V₂(HCl) = 0.02M×0.05L = 0.001mol.

V₁(HCl) = n(HCl) /  C₁(HCl) = 0.001mol/0.5M = 0.002L = 2mL.

It is necessary to take 2mL of 0.5N hydrochloric acid and bring the volume of the solution with distilled water to 50mL.