How many mL of a 10.0% by volume stock solution of HCl must be diluted with enough water to make 300.mL of a 1.5% by volume solution?

To determine how many mL of the 10.0% stock solution of HCl must be diluted, we need to use the concept of dilution.

The formula for dilution is:

C1V1 = C2V2

Where:
C1 = initial concentration of the stock solution
V1 = volume of the stock solution to be diluted
C2 = final concentration of the diluted solution
V2 = final volume of the diluted solution

Let's assign the values to the variables of the formula:

C1 = 10.0% = 0.10 (as a decimal)
V1 = unknown volume of stock solution to be diluted
C2 = 1.5% = 0.015 (as a decimal)
V2 = 300 mL

Now we can substitute these values into the formula and solve for V1:

(0.10)(V1) = (0.015)(300)

0.10V1 = 0.045

Divide both sides by 0.10:

V1 = 0.045 / 0.10

V1 = 0.45

Therefore, you would need to dilute 0.45 mL of the 10.0% stock solution of HCl with enough water to make 300 mL of a 1.5% by volume solution.

The dilution formula is

mL x % = mL x %