Benzene vapour mixed with air when passed over `V_2O_5` catalyst at 775 K give

Options

A. glyoxal
B. oxalic acid
C. maleic anhydride
D. fumaric acid.

Answer

To solve the question, let's break down the process step by step.

### Step 1: Understand the Reactants
We have benzene vapor (C6H6) mixed with air (which contains oxygen, O2). The reaction occurs in the presence of a catalyst, vanadium pentoxide (V2O5), at a high temperature of 775 K.

### Step 2: Identify the Reaction
When benzene is oxidized in the presence of oxygen and a catalyst, it can lead to the formation of various products. In this case, we are looking for the specific products formed under the given conditions.

### Step 3: Determine the Products
The reaction of benzene with oxygen over V2O5 at high temperatures typically leads to the formation of maleic anhydride. The reaction can be summarized as follows:

1. Benzene (C6H6) reacts with oxygen (O2) to form maleic acid (C4H4O4).
2. Maleic acid can then lose a water molecule (H2O) to form maleic anhydride (C4H2O3).

### Step 4: Write the Chemical Equation
The overall reaction can be represented as:
\[ C_6H_6 + O_2 \xrightarrow{V_2O_5, 775 K} C_4H_2O_3 + H_2O \]

### Step 5: Identify the Correct Answer
From the products formed, we see that maleic anhydride is one of the products. Therefore, the correct answer to the question is:
- Maleic Anhydride (C4H2O3)

### Conclusion
Thus, the final answer is that benzene vapor mixed with air when passed over V2O5 catalyst at 775 K gives maleic anhydride.

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