Answer:
The student needs to measure out 6.21mL of the stock solution and dilute it to 125mL with water.
Step-by-step explanation:
To obtain the desired solution, the student need to determine how much of the stock solution she will need.
Now, let us calculate the volume of the stock solution needed.
Data obtained from the question include:
Molarity of the stock solution (M1) = 3.02 M
Volume of the stock solution needed (V1) =...?
Molarity of the diluted solution (M2) = 0.150 M
Volume of the diluted solution (V2) = 125mL
Using the dilution formula, the volume of the stock solution needed can be obtained as follow:
M1V1 = M2V2
3.02 x V2 = 0.15 x 125
Divide both side by 3.02
V2 = (0.15 x 125)/3.02
V2 = 6.21 mL.
Therefore, the student needs to measure out 6.21mL of the stock solution and dilute it to 125mL with water.