How many grams of drug are needed to prepare 150ml of a 2:7 solution?

To determine how many grams of drug are needed to prepare 150 mL of a 2:7 solution, it is important to understand what the ratio 2:7 means. This ratio reflects the proportion of drug to the total parts of the solution. In a 2:7 solution, for every 2 parts of the drug, there are 7 parts in total (the drug + the solvent).

First, we total the parts of the solution: 2 parts (drug) + 7 parts (solvent) = 9 parts total. To find the amount of drug in 150 mL of solution, we will first find the volume represented by each part.

150 mL divided by 9 parts equals approximately 16.67 mL per part. Since the drug makes up 2 of those parts, we multiply the volume per part by the number of parts of the drug:

2 parts × 16.67 mL/part ≈ 33.33 mL of drug.

Next, to find the grams of drug required, we need the concentration of the drug. If we assume the drug has a density or concentration allowing us to convert volume to grams, simply knowing that in this specific context of a