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. (a)6
B. (b)1
C. (c )4
D. (d)2

Explanation

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

### Step 1: Calculate the weight of iron in one mole of hemoglobin
Given that hemoglobin contains 0.33% of iron by weight, we can calculate the weight of iron in one mole of hemoglobin (which has a molecular weight of approximately 67,200 g).

\[ \text{Weight of iron in 1 mole of hemoglobin} = \frac{0.33}{100} \times 67200 \text{ g} \]

### Step 2: Perform the calculation
Now, we will compute the weight of iron:

\[ \text{Weight of iron} = 0.0033 \times 67200 = 221.76 \text{ g} \]

### Step 3: Calculate the number of moles of iron in the weight calculated
Next, we need to find out how many moles of iron are present in 221.76 g of iron. We use the atomic weight of iron (Fe), which is 56 g/mol.

\[ \text{Number of moles of iron} = \frac{\text{Weight of iron}}{\text{Atomic weight of Fe}} = \frac{221.76 \text{ g}}{56 \text{ g/mol}} \]

### Step 4: Perform the calculation
Now, we will compute the number of moles of iron:

\[ \text{Number of moles of iron} = \frac{221.76}{56} \approx 3.96 \text{ moles} \]

### Step 5: Determine the number of iron atoms in one molecule of hemoglobin
Since 1 mole of any substance contains \(6.022 \times 10^{23}\) entities (Avogadro's number), we can round the number of moles of iron to 4 for simplicity. This means that in one molecule of hemoglobin, there are approximately 4 atoms of iron.

### Final Answer
Thus, the number of iron atoms present in one molecule of hemoglobin is approximately **4**.

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