Oxalic acid when heated with `conc. H_2 SO_4` it gives out

Options

A. `H_2 O` and `CO_2`
B. Oxalic sulphate
C. `CO_2` and `H_2 S`
D. `CO` and `CO_2`

Explanation

To solve the question "Oxalic acid when heated with `conc. H2SO4` it gives out", we need to analyze the reaction that occurs when oxalic acid is heated with concentrated sulfuric acid.

### Step-by-Step Solution:

1. **Understand the Reactants**:
- Oxalic acid (C₂H₂O₄) is a dicarboxylic acid with the formula HOOC-COOH.
- Concentrated sulfuric acid (H₂SO₄) is a strong dehydrating agent.

2. **Identify the Reaction**:
- When oxalic acid is heated with concentrated sulfuric acid, the sulfuric acid acts as a dehydrating agent. This means it will remove water (H₂O) from the oxalic acid.

3. **Dehydration Process**:
- The dehydration of oxalic acid leads to the formation of carbon dioxide (CO₂) and carbon monoxide (CO) gases, along with water (H₂O).

4. **Products of the Reaction**:
- The main products formed are:
- Carbon dioxide (CO₂)
- Carbon monoxide (CO)
- Water (H₂O)

5. **Conclusion**:
- Therefore, when oxalic acid is heated with concentrated sulfuric acid, it gives out carbon dioxide (CO₂), carbon monoxide (CO), and water (H₂O).

### Final Answer:
Oxalic acid when heated with concentrated H₂SO₄ gives out **H₂O and CO₂** (and also CO).