Question

If the concentration of a solution desired is 2 mCi/ml and the 325 mCi of solute is contained in a volume of 2.5 ml, how much water should be added to create the solution?

a. 160 ml
b. 162.5 ml
c. 650 ml
d. 125 ml

Answer 1

To create the desired solution, 162.5 ml of water should be added to the solute.

Step-by-step explanation:

To calculate the amount of water needed to create the desired solution, we need to use the concept of dilution.

First, we can calculate the initial concentration of the solute by dividing the amount of solute (325 mCi) by the initial volume of the solution (2.5 ml). This gives us a concentration of 130 mCi/ml.

To calculate the volume of water needed, we can use the dilution formula C1V1 = C2V2, where C represents concentration and V represents volume. We can rearrange the formula to solve for V2, which represents the volume of water needed.

Substituting the given values, we have:

(130 mCi/ml)(2.5 ml) = (2 mCi/ml)(V2)

Solving for V2, we find that V2 is equal to 162.5 ml.

Therefore, the correct answer is option (b) 162.5 ml.