High School

You have prepared 1 liter of intravenous injection solution with 10 mEq of CaCl₂, 10 mEq of KCl, and 9 mEq of NaCl. What is the concentration (mEq/L) of calcium in the solution?

Answer :

The concentration of calcium in the solution is 10 mEq/L.

To determine the concentration of calcium (Ca²⁺) in milliequivalents per liter (mEq/L) in the solution, we can follow these steps:

Step 1: Understand the Relationship Between Milliequivalents and Millimoles

The milliequivalent (mEq) is related to the millimole (mmol) by the valence (charge) of the ion. The formula is:

mEq = mmol x valence

For calcium chloride (CaCl₂), calcium (Ca²⁺) has a valence of 2 (because Ca²⁺ is doubly charged).

Step 2: Calculate the Millimoles of Calcium

Given that the solution contains 10 mEq of CaCl₂, and calcium has a valence of 2, the number of millimoles of calcium is:

[tex]\[\text{mmol of Ca} = \frac{\text{mEq of Ca}}{\text{valence}} = \frac{10 \, \text{mEq}}{2} = 5 \, \text{mmol}\][/tex]

Step 3: Determine the Concentration of Calcium in mEq/L

The concentration of calcium in milliequivalents per liter is given as the total mEq of calcium per liter. Since the total amount of calcium in the solution is 10 mEq, and the volume of the solution is 1 liter, the concentration of calcium is:

[tex]\[\text{Concentration of Ca}^{2+} = 10 \, \text{mEq/L}\][/tex]