How many grams of drug are contained in 500ml of a 20% solution?

To determine how many grams of drug are contained in 500 mL of a 20% solution, it’s essential to understand what a percentage solution represents. A 20% solution means that there are 20 grams of solute for every 100 mL of solution.

To find out how many grams are in 500 mL, you can set up a proportion based on the percentage:

1. We know that 20 grams are in 100 mL.

2. To find out how many grams are in 500 mL, we can set up the calculation:

(20 grams / 100 mL) = (x grams / 500 mL)

3. Cross-multiplying gives us:

20 grams * 500 mL = 100 mL * x grams

4. Solving for x gives:

x = (20 grams * 500 mL) / 100 mL

x = 100 grams

Thus, there are 100 grams of drug in 500 mL of a 20% solution. This understanding of how to manipulate percentages and volume is crucial for pharmacy technicians, as it applies broadly to dosing and preparation of medications.