Determine the number of grams needed for 12.5% solution of 150 mL
The correct answer and explanation is:
To determine the number of grams of solute needed for a 12.5% solution in 150 mL of solution, follow this process:
✅ Correct Answer:
18.75 grams
🔍 Explanation (300 words):
A 12.5% solution typically refers to a weight/volume percent (w/v%), which is a common way to express the concentration of a solution in biology and chemistry. A 12.5% w/v solution means:
12.5 grams of solute per 100 mL of solution
We are given:
- Concentration = 12.5% w/v
- Volume of solution = 150 mL
We use the formula: \text{grams of solute} = \left( \frac{\text{% concentration}}{100} \right) \times \text{volume (mL)}
Substitute the values: grams of solute=(12.5100)×150=0.125×150=18.75 grams\text{grams of solute} = \left( \frac{12.5}{100} \right) \times 150 = 0.125 \times 150 = 18.75 \text{ grams}
🧪 Why This Matters:
In practice, preparing solutions of a specific concentration is fundamental in laboratories, pharmacies, and healthcare. For instance, if a nurse needs to administer a 12.5% glucose solution or a lab technician needs to prepare a 12.5% salt solution, they must calculate the exact amount of solute (in grams) to dissolve in a given volume (in mL) of solvent—usually water.
Using this formula ensures accurate dosing, consistent results, and safe application, whether in medicine, science, or food production. Miscalculating could result in a solution that is either too dilute (ineffective) or too concentrated (potentially harmful).
✅ Summary:
To make 150 mL of a 12.5% solution, you need to weigh out and dissolve 18.75 grams of the solute in enough solvent to make the total volume 150 mL.