When ethyl alcohol is heated with red phosphorus and `HI`, then which of the following is formed

Options

A. Aldehydes
B. Alkoxyalkanes
C. Alkanes
D. Anhydrides

Answer

To solve the question of what is formed when ethyl alcohol (C2H5OH) is heated with red phosphorus and hydrogen iodide (HI), we can follow these steps:

### Step 1: Identify the Reactants
The reactants in this reaction are:
- Ethyl alcohol (C2H5OH)
- Hydrogen iodide (HI)
- Red phosphorus (P)

### Step 2: Understand the Role of Red Phosphorus and HI
Red phosphorus acts as a catalyst in this reaction, while hydrogen iodide is a strong reducing agent. The presence of red phosphorus enhances the reducing ability of HI.

### Step 3: Analyze the Reaction Mechanism
When ethyl alcohol reacts with HI in the presence of red phosphorus:
- The hydroxyl (OH) group of ethyl alcohol is cleaved off.
- A hydrogen ion (H+) from HI attacks the carbon atom that was bonded to the OH group.
- This results in the formation of an alkane.

### Step 4: Write the Reaction
The reaction can be summarized as follows:
\[ \text{C2H5OH} + \text{HI} \xrightarrow{\text{red P}} \text{C2H6} + \text{H2O} + \text{I2} \]
Where C2H6 is ethane, which is an alkane.

### Step 5: Identify the Product
From the reaction, we can see that the product formed is:
- Ethane (C2H6), which is classified as an alkane.

### Step 6: Choose the Correct Option
Given the options:
1. Aldehyde
2. Alkoxy alkanes
3. Alkanes
4. Anhydride

The correct answer is option 3: Alkanes, as the product formed is ethane (C2H6).

### Final Answer
The product formed when ethyl alcohol is heated with red phosphorus and hydrogen iodide is **Alkane (C2H6)**.

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