Alkane can be prepared by

Options

A. at action of Grignard's reagent with water
B. the reduction of alkyl halide with `H_2` in presence of nickel
C. the action of ethereal of alkyl halide with sodium metal
D. all the above

Answer

To prepare alkanes, we can utilize several methods. Let's go through the steps for each method mentioned in the question:

### Step-by-Step Solution:

1. **Preparation of Alkane using Grignard Reagent:**
- Grignard reagents have the general formula R-MgX, where R is an alkyl group and X is a halogen.
- For example, consider CH3MgBr (a Grignard reagent).
- When CH3MgBr reacts with water (H2O), the negative charge from the alkyl group (CH3-) attacks the hydrogen in water.
- This results in the formation of methane (CH4) and magnesium hydroxide bromide (MgBrOH) as a by-product.
- **Conclusion:** Grignard reagents can successfully produce alkanes.

2. **Preparation of Alkane by Reduction of Alkyl Halide:**
- Alkyl halides (RX) can be reduced to alkanes using hydrogen in the presence of a catalyst like nickel.
- For example, CH3Cl (methyl chloride) can be treated with hydrogen (H2) in the presence of nickel.
- The reaction results in the formation of methane (CH4) and hydrochloric acid (HCl).
- **Conclusion:** Alkyl halides can also be converted into alkanes through reduction.

3. **Preparation of Alkane via Wurtz Reaction:**
- The Wurtz reaction involves the reaction of alkyl halides with sodium metal in the presence of ether.
- For instance, if we take two moles of CH3Cl and react them with sodium in ether, we can obtain ethane (C2H6).
- The reaction can be represented as:
\[ 2 \text{CH}_3\text{Cl} + 2 \text{Na} \rightarrow \text{C}_2\text{H}_6 + 2 \text{NaCl} \]
- **Conclusion:** This method also successfully yields alkanes.

4. **Final Conclusion:**
- Since all three methods discussed (Grignard reagent reaction, reduction of alkyl halides, and Wurtz reaction) can prepare alkanes, the most appropriate answer is that all of the above methods are correct.

### Final Answer:
**D. All of the above.**

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