A compound contains `3.2%` of oxygen. The minimum mol. Wt. of the compound is

Options

A. 300
B. 440
C. 350
D. 500

Answer

To find the minimum molecular weight of a compound that contains 3.2% oxygen, we can follow these steps:

### Step-by-Step Solution:

1. **Define the Molecular Weight**:
Let the minimum molecular weight of the compound be \( x \) grams.

2. **Identify the Mass of Oxygen**:
The compound contains at least one oxygen atom. The molar mass of oxygen is 16 grams. Therefore, in \( x \) grams of the compound, the mass of oxygen will be 16 grams.

3. **Set Up the Percentage Equation**:
According to the problem, the mass of oxygen constitutes 3.2% of the total mass of the compound. Therefore, we can express this as:
\[ \frac{16 \text{ g}}{x} \times 100 = 3.2 \]

4. **Rearrange the Equation**:
To find \( x \), we rearrange the equation:
\[ 16 \text{ g} = \frac{3.2}{100} \times x \]

5. **Solve for \( x \)**:
Multiply both sides by 100 to eliminate the fraction:
\[ 1600 = 3.2x \]
Now, divide both sides by 3.2:
\[ x = \frac{1600}{3.2} \]

6. **Calculate \( x \)**:
Performing the division:
\[ x = 500 \text{ g} \]

7. **Conclusion**:
Therefore, the minimum molecular weight of the compound is \( 500 \) grams.

### Final Answer:
The minimum molecular weight of the compound is \( 500 \) grams (Option D).