Question

Rigner's solution contains 0.33 g of Calcium chloride per liter. Express the concentration in terms of mEq of Calcium chloride (CaCl2.H2O, MWt=147) per liter. A. 4.5 mEq/L C. 2.24 mEq/L B. 6.73 mEq/L D. 8.98 mEq/L

Answer 1

The concentration of Calcium chloride (CaCl2.H2O) in Ringer's solution is approximately 4.49 mEq/L. This value is closest to option A) 4.5 mEq/L.

To express the concentration of Calcium chloride (CaCl2.H2O) in terms of milliequivalents per liter (mEq/L), we need to follow these steps:

1. Calculate the Molarity of the Solution:

- Molarity is given by the formula:
`\( \text{Moles of solute} / \text{Liters of solution} \).`

- One mole of Calcium chloride dihydrate (CaCl2.H2O) has a molecular weight of 147 g/mol.

2. Convert Molarity to Millimolarity:

- Since we're dealing with milliequivalents, we need to express the molarity in millimoles per liter (mmol/L).

3. Calculate Milliequivalents per Liter:

- Each mole of CaCl2 contributes two equivalents (one from Ca²⁺ and two from two Cl⁻, but one of these is balanced by the Ca²⁺).

- Therefore, milliequivalents per liter (mEq/L) = millimolarity × valence of the solute.

Let's perform the calculations:

- Given: 0.33 g of CaCl2.H2O per liter

- Molar mass of CaCl2.H2O = 147 g/mol

Step 1: Calculate the Molarity (M) =
`\( \frac{0.33 \text{ g/L}}{147 \text{ g/mol}} \)`

Step 2: Convert Molarity to Millimolarity (mmol/L)

Step 3: Calculate mEq/L = mmol/L × valence

The concentration of Calcium chloride (CaCl2.H2O) in Ringer's solution is approximately 4.49 mEq/L. This value is closest to option A) 4.5 mEq/L.