Question

You are required to make 10mL of a 0.5M solution of HCl. Your stock solution of HCl is 90M. Using distilled water (dH2O) as a solvent, how much of each component will you need to make the desired final solution?

Answer 1

0.0556 mL of 90 M HCl would be taken and 9.944 mL distilled water added to make 0.5 M, 10 mL HCl solution.

Step-by-step explanation:

From the dilution equation:

Initial molarity (m1) x initial volume (v1) = final molarity (m2) x final volume (v2).

In this case, m1 = 90 M, v1 = ?, m2 = 0.5 M, and v2 = 10 mL

v1 = m2 x v2/ m1 = 0.5 x 0.01/90 = 0.0000556 L

v1 = 0.0556 mL

This means that the initial volume of 90 M HCl to be taken is 0.0556 mL. Since the final volume to be prepared is 10 mL,

10 - 0.0556 = 9.944 mL

Hence, 0.0556 mL of 90 M HCl would be taken and 9.944 mL distilled water added to make 0.5 M, 10 mL HCl solution.