Hydrochloric acid is typically purchased in a relatively highly concentrated form and then diluted by adding slowly to water to save money. The concentration of the purchased solution is 37.0% by mass HCl, and this solution has a density of 1.20 g/mL.

Question

Hydrochloric acid is typically purchased in a relatively highly concentrated form and then diluted by adding slowly to water to save money.  The concentration of the purchased solution is 37.0% by mass HCl, and this solution has a density of 1.20 g/mL.

What volume of the concentrated HCl solution is the correct amount needed to make 3.7 L of 0.435 M HCl?  Please express your answer in mL.

The answer is _________ mL.

DrBob222 · Accepted Answer

Two steps.
1.First, determine the molarity of the 37% HCl.
2. Second, work on the dilutions.
First:
1.20 g/mL x 1,000 mL x 0.37 x (1/36.5) = 12.2 M
Second: Use the dilution formula
mL1 x M1 = mL2 x M2
mL1 x 12.2 = 3,700 mL x 0.435 M
Solve for mL1 which is the amount of the 12.2 M stuff that should be taken.