Chlorophyll is a biomolecule responsible for green colour in the plants. Chlorophyll contains `2.68%` of magnesium by mass. Calculate the number of magnesium atoms in `6 g` of chlorophyll `(Mg = 24)`

Options

A. `2.01 xx 10^(21)`
B. `4.03 xx 10^(21)`
C. `6.02 xx 10^(23)`
D. `4.03 xx 10^(23)`

Answer

To solve the problem of calculating the number of magnesium atoms in 6 g of chlorophyll, we can follow these steps:

### Step 1: Calculate the mass of magnesium in 6 g of chlorophyll
Given that chlorophyll contains 2.68% magnesium by mass, we can find the mass of magnesium in 6 g of chlorophyll using the formula:

\[ \text{Mass of Mg} = \left(\frac{2.68}{100}\right) \times 6 \, \text{g} \]

Calculating this gives:

\[ \text{Mass of Mg} = 0.1608 \, \text{g} \]

### Step 2: Convert the mass of magnesium to moles
To find the number of atoms, we first need to convert the mass of magnesium to moles using the molar mass of magnesium (Mg = 24 g/mol):

\[ \text{Moles of Mg} = \frac{\text{Mass of Mg}}{\text{Molar mass of Mg}} = \frac{0.1608 \, \text{g}}{24 \, \text{g/mol}} \]

Calculating this gives:

\[ \text{Moles of Mg} = 0.0067 \, \text{mol} \]

### Step 3: Calculate the number of magnesium atoms
Using Avogadro's number (\(6.02 \times 10^{23}\) atoms/mol), we can find the number of magnesium atoms:

\[ \text{Number of Mg atoms} = \text{Moles of Mg} \times \text{Avogadro's number} \]

Substituting the values gives:

\[ \text{Number of Mg atoms} = 0.0067 \, \text{mol} \times 6.02 \times 10^{23} \, \text{atoms/mol} \]

Calculating this gives:

\[ \text{Number of Mg atoms} \approx 4.02 \times 10^{21} \, \text{atoms} \]

### Final Answer
Thus, the number of magnesium atoms in 6 g of chlorophyll is approximately \(4 \times 10^{21}\) atoms.

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