Haemoglobin contains 0.33% of iron by weight. The molecular weight of heamoglobin is approximately 67200. The number of iron atoms (At. Wt. of Fe=56) present in one molecule of haemoglobin is

Options

A. 1
B. 6
C. 4
D. 2

Explanation

To find the number of iron atoms present in one molecule of hemoglobin, we can follow these steps:

### Step 1: Calculate the weight of iron in one mole of hemoglobin
Given:
- Molecular weight of hemoglobin = 67200 g/mol
- Percentage of iron in hemoglobin = 0.33%

To find the weight of iron in one mole of hemoglobin:
\[ \text{Weight of Fe} = \left( \frac{0.33}{100} \right) \times 67200 \]

### Step 2: Perform the calculation
Calculating the weight of iron:
\[ \text{Weight of Fe} = 0.0033 \times 67200 = 222.96 \text{ g} \]
For simplicity, we can round this to 222 g.

### Step 3: Calculate the number of iron atoms
The atomic weight of iron (Fe) is given as 56 g/mol. To find the number of iron atoms in 222 g of iron:
\[ \text{Number of moles of Fe} = \frac{222 \text{ g}}{56 \text{ g/mol}} \]

### Step 4: Perform the calculation
Calculating the number of moles of iron:
\[ \text{Number of moles of Fe} = \frac{222}{56} \approx 3.964 \text{ moles} \]

### Step 5: Convert moles to atoms
Using Avogadro's number (approximately \(6.022 \times 10^{23}\) atoms/mol), we can find the number of iron atoms:
\[ \text{Number of Fe atoms} = 3.964 \text{ moles} \times 6.022 \times 10^{23} \text{ atoms/mole} \]

Since we are looking for the number of iron atoms in one molecule of hemoglobin, we can consider the ratio of moles of iron to moles of hemoglobin. Since we are calculating for one molecule of hemoglobin, we can simplify our earlier calculation to find the number of iron atoms directly.

### Final Calculation
Since we found that there are approximately 4 moles of iron in 1 mole of hemoglobin, we can conclude that there are approximately 4 iron atoms in one molecule of hemoglobin.

### Conclusion
The number of iron atoms present in one molecule of hemoglobin is **4**.

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