Concentrated hydrochloric acid, HCl, comes with an approximate molar concentration of 12.1 M. If you are instructed to prepare 350.0 mL of a 0.975 M HCl solution, how many milliliters of the stock (concentrated) HCl solution will you use

28.20 mL of the stock solution.

Explanation:

Data obtained from the question include the following:

Molarity of stock solution (M1) = 12.1 M

Volume of diluted solution (V2) = 350.0 mL

Molarity of diluted solution (M2) = 0.975 M

Volume of stock solution needed (V1) =..?

The volume of stock solution needed can be obtained by using the dilution formula as shown below:

M1V1 = M2V2

12.1 x V1 = 0.975 x 350

Divide both side by 12.1

V1 = (0.975 x 350)/12.1

V1 = 28.20 mL.

Therefore, 28.20 mL of the stock solution will be needed to prepare 350.0 mL of 0.975 M HCl solution.