Calculate the number of molecules of sulphur `(S_(8))` present in 16 g of solid sulphur.

Explanation

To calculate the number of molecules of sulfur (S₈) present in 16 g of solid sulfur, we can follow these steps:

### Step 1: Determine the atomic mass of sulfur
The atomic mass of sulfur (S) is given as 32 g/mol.

### Step 2: Calculate the molecular mass of S₈
Since one molecule of sulfur (S₈) consists of 8 sulfur atoms, we can calculate the molecular mass of S₈ as follows:
\[ \text{Molecular mass of } S₈ = 8 \times \text{Atomic mass of S} = 8 \times 32 \, \text{g} = 256 \, \text{g/mol} \]

### Step 3: Use the mole concept
According to the mole concept, 1 mole of any substance contains \(6.022 \times 10^{23}\) entities (Avogadro's number). Therefore, 1 mole of S₈ (which has a mass of 256 g) contains \(6.022 \times 10^{23}\) molecules of S₈.

### Step 4: Calculate the number of moles in 16 g of S₈
To find the number of moles of S₈ in 16 g, we use the formula:
\[ \text{Number of moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}} \]
Substituting the values:
\[ \text{Number of moles of } S₈ = \frac{16 \, \text{g}}{256 \, \text{g/mol}} = 0.0625 \, \text{moles} \]

### Step 5: Calculate the number of molecules in 0.0625 moles of S₈
Now, we can calculate the number of molecules in 0.0625 moles of S₈ using Avogadro's number:
\[ \text{Number of molecules} = \text{Number of moles} \times 6.022 \times 10^{23} \]
Substituting the values:
\[ \text{Number of molecules} = 0.0625 \, \text{moles} \times 6.022 \times 10^{23} \approx 3.76 \times 10^{22} \, \text{molecules} \]

### Final Answer
Thus, the number of molecules of sulfur (S₈) present in 16 g of solid sulfur is approximately \(3.76 \times 10^{22}\) molecules.

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