`0.1 g` of metal combines with `46.6 mL` of oxygen at `STP`. The equivalent weight of metal is

Options

A. 12
B. 24
C. 6
D. 36

Explanation

To find the equivalent weight of the metal that combines with oxygen, we can follow these steps:

### Step 1: Calculate the number of moles of oxygen (O₂)
We know that at STP (Standard Temperature and Pressure), 22,400 mL of O₂ contains 1 mole of oxygen. Therefore, we can calculate the number of moles of O₂ in 46.6 mL using the formula:

\[ \text{Number of moles of O}_2 = \frac{\text{Volume of O}_2}{\text{Molar volume at STP}} = \frac{46.6 \, \text{mL}}{22400 \, \text{mL/mol}} \]

Calculating this gives:

\[ \text{Number of moles of O}_2 = \frac{46.6}{22400} \approx 0.00208 \, \text{mol} \]

### Step 2: Calculate the equivalent weight of oxygen
The equivalent weight of a substance can be calculated using the formula:

\[ \text{Equivalent weight} = \frac{\text{Molar mass}}{\text{Valency factor}} \]

For oxygen (O₂), the molar mass is 32 g/mol and the valency factor is 2 (since O₂ can provide 2 moles of electrons in reactions). Therefore:

\[ \text{Equivalent weight of O}_2 = \frac{32 \, \text{g/mol}}{2} = 16 \, \text{g/equiv} \]

### Step 3: Calculate the total equivalents of oxygen used
Now, we can find the total equivalents of oxygen that reacted:

\[ \text{Equivalents of O}_2 = \text{Number of moles} \times \text{Valency factor} = 0.00208 \, \text{mol} \times 2 = 0.00416 \, \text{equiv} \]

### Step 4: Calculate the equivalent weight of the metal
The equivalent weight of the metal can be calculated using the formula:

\[ \text{Equivalent weight of metal} = \frac{\text{Weight of metal}}{\text{Equivalents of metal}} \]

Since the metal and oxygen react in equivalent amounts, the equivalents of the metal will be equal to the equivalents of oxygen:

\[ \text{Weight of metal} = 0.1 \, \text{g} \]

Substituting the values we have:

\[ \text{Equivalent weight of metal} = \frac{0.1 \, \text{g}}{0.00416 \, \text{equiv}} \approx 24.04 \, \text{g/equiv} \]

### Final Calculation
After calculating, we find that the equivalent weight of the metal is approximately:

\[ \text{Equivalent weight of metal} \approx 24.04 \, \text{g/equiv} \]

### Conclusion
Thus, the equivalent weight of the metal is approximately **24 g/equiv**.

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