Question

Using the 13.4-mg/ml solution from question 1, how could the analyst perform a serial dilution to prepare a 1.0-mg/ml solution of analyte?

a) Add 13.4 ml to 100 ml
b) Add 1 ml to 13.4 ml
c) Add 10 ml to 100 ml
d) Add 1 ml to 10 ml

Answer 1

To prepare a 1.0-mg/ml solution from a 13.4-mg/ml stock solution, adding 1 ml of the stock solution to 10 ml of solvent (option d) will result in the desired concentration after mixing.

Step-by-step explanation:

Performing a serial dilution to prepare a 1.0-mg/ml solution from a 13.4-mg/ml stock solution requires calculating the right volumes to mix. Option (d) Add 1 ml to 10 ml is correct. By adding 1 ml of the 13.4-mg/ml solution to 10 ml of solvent, you make a total volume of 11 ml. The dilution factor is 1+10 = 11. To find the concentration of the new solution, use the equation C1V1 = C2V2, where C1 is the initial concentration, V1 is the volume of the stock solution, C2 is the final concentration, and V2 is the total volume of the diluted solution. Here, 13.4 mg/ml * 1 ml = 1.0 mg/ml * 11 ml; thus, after the dilution, the concentration will be 1.0 mg/ml.