Concentration of Ca ion in blood plasma is(approximately)

Options

A. `10 mg L^(-1)`
B. `100 mg L^(-1)`
C. `50 mg L^(-1)`
D. `25 mg L^(-1)`

Answer

To determine the concentration of calcium ions (Ca²⁺) in blood plasma, we can follow these steps:

### Step 1: Understand the Normal Range
The normal concentration of calcium ions in blood plasma is typically given in milliequivalents per liter (mEq/L). The normal range for calcium ions is approximately 4.5 to 5.1 mEq/L.

### Step 2: Convert to Milligrams per Liter
To convert the concentration from mEq/L to mg/L, we need to know the molar mass of calcium. The molar mass of calcium (Ca) is approximately 40.08 g/mol.

1. **Calculate the equivalent weight of calcium**: Since calcium has a valency of +2, the equivalent weight is:
\[ \text{Equivalent weight of Ca} = \frac{\text{Molar mass of Ca}}{\text{Valency}} = \frac{40.08 \, \text{g/mol}}{2} = 20.04 \, \text{g/equiv} \]

2. **Convert mEq/L to mg/L**:
- For 4.5 mEq/L:
\[ 4.5 \, \text{mEq/L} \times 20.04 \, \text{g/equiv} = 90.18 \, \text{mg/L} \]
- For 5.1 mEq/L:
\[ 5.1 \, \text{mEq/L} \times 20.04 \, \text{g/equiv} = 102.20 \, \text{mg/L} \]

### Step 3: Determine the Range in mg/L
From the calculations:
- The concentration of calcium ions in blood plasma is approximately between 90 mg/L to 102 mg/L.

### Step 4: Identify the Correct Option
Given the options, we see that the concentration of calcium ions in blood plasma can be represented as:
- 100 mg/L, which falls within the calculated range of 90 to 102 mg/L.

### Conclusion
Thus, the concentration of calcium ions in blood plasma is approximately 100 mg/L.

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