The molar concentration of 64 g of `SO_(2)` in a four litre flask would be

Options

A. 2
B. 1
C. 5
D. 0.25

Answer

To find the molar concentration of 64 g of SO₂ in a four-litre flask, we will follow these steps:

### Step 1: Calculate the molar mass of SO₂
The molar mass of SO₂ can be calculated using the atomic masses of sulfur (S) and oxygen (O):
- Atomic mass of sulfur (S) = 32 g/mol
- Atomic mass of oxygen (O) = 16 g/mol

Since there are two oxygen atoms in SO₂:
\[ \text{Molar mass of SO₂} = \text{mass of S} + 2 \times \text{mass of O} = 32 \, \text{g/mol} + 2 \times 16 \, \text{g/mol} = 32 \, \text{g/mol} + 32 \, \text{g/mol} = 64 \, \text{g/mol} \]

### Step 2: Calculate the number of moles of SO₂
Using the formula for moles:
\[ \text{Number of moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}} \]
Substituting the values:
\[ \text{Number of moles} = \frac{64 \, \text{g}}{64 \, \text{g/mol}} = 1 \, \text{mol} \]

### Step 3: Calculate the molarity
Molarity (M) is defined as the number of moles of solute per litre of solution:
\[ \text{Molarity (M)} = \frac{\text{Number of moles}}{\text{Volume (L)}} \]
Substituting the values:
\[ \text{Molarity (M)} = \frac{1 \, \text{mol}}{4 \, \text{L}} = 0.25 \, \text{mol/L} \]

### Final Answer
The molar concentration of 64 g of SO₂ in a four-litre flask is **0.25 mol/L**.

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