Question 70

The final percentage strength of the drug is 6.67%

When a 20% (v/v) solution of a drug is diluted from 500 mL to 1500 mL, the final percentage strength can be calculated using the formula: (C1V1 = C2V2). This results in a final concentration of 6.67%.

A) 1.77%

Option A is incorrect because 1.77% does not represent the outcome of diluting a 20% solution to a larger volume. The calculations for dilution do not support this percentage as the final strength.

B) 3.23%

Option B is also incorrect as it fails to reflect the appropriate dilution calculations. The dilution of a 20% solution to 1500 mL does not yield a concentration of 3.23%.

C) 6.67%

This option is correct as it accurately reflects the final concentration after diluting 500 mL of a 20% solution to 1500 mL. Using the dilution formula, the resulting concentration is calculated to be 6.67%.

D) 8.95%

Option D is incorrect because the final strength of 8.95% does not match the calculated outcome of the dilution process. The dilution would not lead to this percentage based on the initial concentration and final volume.

Conclusion

The correct answer is 6.67%, as it accurately calculates the final percentage strength after diluting a 20% solution to a total volume of 1500 mL. All other options fail to represent the correct calculations based on the principles of dilution, making them incorrect. This highlights the importance of understanding dilution ratios in concentration problems.