Question 50

11.25 mL of a 10% potassium chloride solution is needed to provide one 15 mEq dose of KCl.

To determine the volume required to supply a single 15 mEq dose of KCl, we use the information that a 10% potassium chloride solution provides 20 mEq in 15 mL. This ratio allows us to calculate the necessary volume for 15 mEq.

A) 8 mL

Selecting 8 mL would yield a lower dosage than required. Given that 15 mL of the solution provides 20 mEq, using 8 mL would result in less than the 15 mEq needed, thereby making this option incorrect.

B) 11.25 mL

This option is correct. To find the appropriate volume, we set up a ratio based on the known concentration: \( \frac{20 \text{ mEq}}{15 \text{ mL}} = \frac{15 \text{ mEq}}{x \text{ mL}} \). Solving for x gives \( x = 11.25 \text{ mL} \), which accurately provides the 15 mEq dose of KCl required.

C) 15 mL

Choosing 15 mL would provide the full 20 mEq of potassium chloride. While this volume is sufficient to meet the dosage requirement, it exceeds the necessary amount, making it an incorrect choice for this specific question.

D) 20 mL

This option also exceeds the required dosage. Using 20 mL would deliver a total of 26.67 mEq (since 20 mL results in \( \frac{20 \text{ mEq}}{15 \text{ mL}} \times 20 \text{ mL} = 26.67 \text{ mEq} \)), which is significantly higher than the 15 mEq needed. Therefore, this option is incorrect.

Conclusion

The calculation clearly demonstrates that 11.25 mL is the precise volume needed to provide a 15 mEq dose of KCl, confirming that Option B is the accurate choice. All other options either under-deliver or over-deliver the required dosage, failing to meet the specific requirement of the question.