Question

PLEASE HELP !

You need to work with a solution of hydrochloric acid in a concentration of 3 moles/L. However, you only have a 2L solution of hydrochloric acid with a concentration of 6 moles per liter. How much water do you need to add to your initial solution to have the molarity of 3 moles/L you are required?

Answer 1

2L of water.

Step-by-step explanation:

To know the volume of water to be added to the initial solution, first let us calculate the volume of the final solution. This is illustrated below:

Data obtained from the question:

Initial volume (V1) = 2L

Initial concentration (C1) = 6mol/L

Final concentration (C2) = 3mol/L

Final volume (V2) =?

Using the dilution formula, we can obtain the final volume of the stock as follow:

C1V1 =C2V2

6 x 2 = 3 x V2

Divide both side by 3

V2 = (6 x 2)/3

V2 = 4L.

The final volume of the solution is 4L.

To obtain the volume of water added, we shall determine the change in the volume of the solution. This is illustrated below:

Initial volume (V1) = 2L

Final volume (V2) = 4L

Change in volume = V2 – V1 = 4 – 2 = 2L.

Therefore, 2L of water must be added to the initial solution.