The reaction of `HCOOH` with `conc. H_2 SO_4` gives :

Options

A. `CO_2`
B. `CO`
C. Oxalic acid
D. Acetic acid

Answer

To solve the question regarding the reaction of formic acid (HCOOH) with concentrated sulfuric acid (H₂SO₄), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**: The reactants in this reaction are formic acid (HCOOH) and concentrated sulfuric acid (H₂SO₄).

2. **Understand the Role of Concentrated H₂SO₄**: Concentrated sulfuric acid is known to act as a dehydrating agent. This means it can remove water (H₂O) from other substances during a chemical reaction.

3. **Consider the Reaction Mechanism**: When formic acid is heated with concentrated sulfuric acid, the concentrated sulfuric acid facilitates the removal of water from the formic acid molecule. This dehydration process leads to the formation of carbon monoxide (CO) and water (H₂O).

4. **Write the Balanced Reaction**: The reaction can be summarized as follows:
\[ \text{HCOOH} \xrightarrow{\text{conc. } H_2SO_4} \text{CO} + \text{H}_2\text{O} \]
In this reaction, formic acid decomposes into carbon monoxide and water.

5. **Identify the Product**: From the above reaction, we can see that the primary gaseous product formed is carbon monoxide (CO).

6. **Select the Correct Option**: Based on the options provided:
- Option A: CO₂ (Carbon Dioxide)
- Option B: CO (Carbon Monoxide)
- Option C: Oxalic Acid
- Option D: Acetic Acid

The correct answer is **Option B: CO (Carbon Monoxide)**.

### Summary:
The reaction of formic acid (HCOOH) with concentrated sulfuric acid (H₂SO₄) produces carbon monoxide (CO) and water (H₂O).

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