Question

You have 285 mL of a 0.125 M HCl solution and you want to dilute as much of it as possible IN ONE DILUTION to 0.100 M. Describe the procedure taken. Remember how to use the volumetric flasks, which come in sizes on 10.00 mL, 50.00 mL, 250.00 mL, 500.00 mL, and 1.00 L.

Answer 1

use dilution formula

M1*V1 = M2*V2

Here:

M1 is molarity of solution before dilution

M2 is molarity of solution after dilution

V1 is volume of solution before dilution

V2 is volume of solution after dilution

we have:

M1 = 0.125 M

M2 = 0.1 M

V1 = 285.0 mL

we have below equation to be used:

M1*V1 = M2*V2

V2 = (M1 * V1) / M2

V2 = (0.125*285)/0.1

V2 = 356.25 mL

Maximum volume that can be made is 356 mL

So, flask size should be less than that

We have to use 250 mL flask

let find the volume of stock solution required then

we have:

M1 = 0.125 M

M2 = 0.1 M

V2 = 250.0 mL

we have below equation to be used:

M1*V1 = M2*V2

V1 = (M2 * V2) / M1

V1 = (0.1*250)/0.125

V1 = 200 mL

so we take 200 mL of stock solution in 250 mL flask and dilute with water till mark