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: Determine the mass of magnesium in 6 g of chlorophyll
Given that chlorophyll contains 2.68% magnesium by mass, we can calculate the mass of magnesium in 6 g of chlorophyll.

\[ \text{Mass of magnesium} = \frac{2.68}{100} \times 6 \text{ g} = 0.1608 \text{ g} \]

### Step 2: Calculate the number of moles of magnesium
To find the number of moles of magnesium, we use the formula:

\[ \text{Number of moles} = \frac{\text{mass}}{\text{molar mass}} \]

The molar mass of magnesium (Mg) is given as 24 g/mol. Therefore:

\[ \text{Number of moles of magnesium} = \frac{0.1608 \text{ g}}{24 \text{ g/mol}} = 0.0067 \text{ moles} \]

### Step 3: Calculate the number of magnesium atoms
To find the number of atoms, we use Avogadro's number, which is \(6.022 \times 10^{23}\) atoms/mol. The relationship is given by:

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

Substituting the values we have:

\[ \text{Number of atoms of magnesium} = 0.0067 \text{ moles} \times 6.022 \times 10^{23} \text{ atoms/mol} \]

Calculating this gives:

\[ \text{Number of atoms of magnesium} \approx 4.03 \times 10^{21} \text{ atoms} \]

### Final Answer
The number of magnesium atoms in 6 g of chlorophyll is approximately \(4.03 \times 10^{21}\) atoms.

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