Final answer:
To prepare a 5.0% D5W solution from a 29% stock solution, calculate the volume of stock solution needed using the dilution formula C1V1 = C2V2. You will need approximately 86.21 mL of the stock solution and then dilute it with water to make a total volume of 500 mL.
Step-by-step explanation:
To prepare 500 mL of a 5.0% dextrose solution (D5W) from a 29% stock solution, you need to dilute the stock solution. The amount of dextrose needed is 5% of 500 mL, which is 25 grams. Since the stock solution is 29% dextrose, we need to calculate how much of this stock solution will provide the 25 grams of dextrose.
You can use the following formula for dilution: C1V1 = C2V2. Where:
C1 = concentration of the stock solution (29%)
V1 = volume of the stock solution needed
C2 = desired concentration (5%)
V2 = desired final volume (500 mL)
Calculation:
(29%)(V1) = (5%)(500 mL)
V1 = (5%)(500 mL) / 29%
Convert percentages to decimal form:
V1 = (0.05)(500 mL) / 0.29
Thus, the volume (V1) needed from the stock solution is approximately 86.21 mL. The rest of the volume up to 500 mL should be made up with water.