1. The percent strength is calculated by taking the mass of the drug and dividing by the total volume of the solution, then multiplying by 100.
P = \left( \frac{m}{V} \right) \times 100
2. For this problem:
m = 9 \, \text{grams}
V = 100 \, \text{ml}
3. Substitute the given values into the formula:
P = \left( \frac{9}{100} \right) \times 100
4. Simplify:
P = 9\%
Therefore, the percent strength of solution is
P = 9\%