The gas(es) used in the hydrogenation of oils in presence of nickel as a catalyst is/are:

Options

A. methane
B. ethane
C. ozone
D. hydrogen

Answer

To solve the question regarding the gas used in the hydrogenation of oils in the presence of nickel as a catalyst, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Hydrogenation**:
- Hydrogenation is a chemical reaction that involves the addition of hydrogen (H₂) to unsaturated compounds, such as vegetable oils, which contain double bonds (C=C).

2. **Identifying the Reactants**:
- The primary reactant in the hydrogenation of oils is the unsaturated vegetable oil, which can be represented as R-C=C-R (where R represents hydrocarbon chains).

3. **Role of Catalyst**:
- Nickel (Ni) is commonly used as a catalyst in this reaction. A catalyst speeds up the reaction without being consumed in the process.

4. **Adding Hydrogen Gas**:
- During the hydrogenation process, hydrogen gas (H₂) is introduced to the reaction mixture. The hydrogen atoms will add across the double bonds of the unsaturated oil.

5. **Formation of Saturated Oil**:
- The result of this reaction is the conversion of unsaturated vegetable oil into saturated fat (ghee), which can be represented as R-CH₂-CH₂-R (where the double bond has been replaced by single bonds).

6. **Conclusion**:
- Therefore, the gas used in the hydrogenation of oils in the presence of nickel as a catalyst is hydrogen gas (H₂).

### Final Answer:
The gas used in the hydrogenation of oils in the presence of nickel as a catalyst is hydrogen (H₂).