Final answer:
The student's question involves finding the volume of a stock solution needed to obtain a desired concentration in a final solution, using the standard dilution equation C1V1 = C2V2. It appears the student needs to determine how much of a stock solution with a concentration of 2000 µg/µL is required to achieve a final concentration of 500 µg in 40 µL.
Step-by-step explanation:
The student is asking about dilution calculations for a stock solution in a laboratory setting, specifically finding the required volume of a stock solution to achieve a desired concentration in a new solution volume. The equation that typically would be used here is “C1V1 = C2V2”, where C1 and V1 are the concentration and volume of the stock solution, respectively, and C2 and V2 are the concentration and volume of the desired final solution.
In this case, the equation provided seems to imply that the stock concentration is 2000 µg/µL, the final concentration required is 500 µg in a total volume of 40 µL. To find the volume of stock needed (V1), we can rearrange the equation to V1 = C2V2/C1.
Given the concentrations and volumes, the calculation would be V1 = (500 µg * 40 µL) / 2000 µg/µL, simplifying to V1 = 20 µL of stock solution needed.