You wish to make a 0.283 M hydrobromic acid solution from a stock solution of 12.0 M hydrobromic acid. How much concentrated acid must you add to obtain a total volume of 75.0 mL of the dilute solution

1.77 mL

Explanation:

To solve this problem we going to use the following equation:

[1] X v1 = [2] X v2

Where:

[1] = will be the higher concentration, the stock solution.

[ 2 ] = will be the concentration that you want to obtain.

v1 = the volume you have to take from the stock solution

v2 = the volume of the solution you will prepare

Replacing the data on the equation:

[1] = 12 M

[2] = 0.283 M

v1 = ?, that's the volume you want to find.

v2 = 75 mL

Using the equation:

12 M x v1 = 0.283 M x 75 mL

v1 = (0.283x75) / 12

v1 = 1.77 mL