You have 5 L of a 9 M stock solution. You need to make 750 mL of a 3M solution. What volume of the stock needs to be added to the new solution?
To calculate how much of the stock solution needs to be added to the new solution, we can use the formula:
C1V1 = C2V2
Where:
C1 = concentration of the stock solution (9 M)
V1 = volume of the stock solution to be added
C2 = concentration of the new solution (3 M)
V2 = total volume of the new solution (750 mL)
Plugging in the values we have:
(9 M)(V1) = (3 M)(750 mL)
9V1 = 2250
V1 = 250 mL
Therefore, you will need to add 250 mL of the 9 M stock solution to the new solution to achieve a concentration of 3 M.