One gm equivalent of substance present in :-

Options

A. `0.25 "mole" O_(2)`
B. `0.5 "mole" of O_(2)`
C. `1.00 "mole" of O_(2)`
D. `8.00 "mole" of O_(2)`

Explanation

To solve the question regarding the mass of a substance that corresponds to one gram equivalent, we will follow these steps:

### Step-by-Step Solution:

1. **Understanding Gram Equivalent**:
- A gram equivalent of a substance is defined as the mass of that substance which will combine with or displace one mole of hydrogen or 8 grams of oxygen.

2. **Identify the Molecular Weight of Oxygen**:
- The molecular weight of O2 (oxygen) is 32 g/mol (since each oxygen atom has an atomic weight of 16 g).

3. **Calculate the Mass for One Gram Equivalent of O2**:
- Since one gram equivalent of oxygen corresponds to 8 grams (as it displaces 1 mole of hydrogen), we can relate this to the number of moles.
- The number of moles of O2 that corresponds to 8 grams can be calculated using the formula:
\[ \text{Number of moles} = \frac{\text{Weight}}{\text{Molecular Weight}} \]
- For O2:
\[ \text{Number of moles} = \frac{8 \text{ g}}{32 \text{ g/mol}} = 0.25 \text{ moles} \]

4. **Conclusion**:
- Therefore, one gram equivalent of substance is present in 0.25 moles of O2.

### Final Answer:
One gram equivalent of substance is present in **0.25 moles of O2**.

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