Which benzene sulphonic acid and `p-`nitrophenol are treated with `NaHCO_3`, the gases released, respectively are :

Options

A. `SO_2,NO_2`
B. `SO_2,NO`
C. `SO_2,CO_2`
D. `CO_2,CO_2`

Explanation

To solve the problem, we need to analyze the reactions of benzene sulfonic acid and para-nitrophenol when treated with sodium bicarbonate (NaHCO₃).

### Step-by-Step Solution:

1. **Identify the Reactants**:
- The first reactant is benzene sulfonic acid (C₆H₅SO₃H).
- The second reactant is para-nitrophenol (C₆H₄(NO₂)OH).

2. **Reaction of Benzene Sulfonic Acid with NaHCO₃**:
- Benzene sulfonic acid is a strong acid. When it reacts with sodium bicarbonate (NaHCO₃), it will produce sodium benzene sulfonate (C₆H₅SO₃Na), water (H₂O), and carbon dioxide (CO₂).
- The reaction can be written as:
\[ C₆H₅SO₃H + NaHCO₃ \rightarrow C₆H₅SO₃Na + H₂O + CO₂ \]

3. **Reaction of Para-Nitrophenol with NaHCO₃**:
- Para-nitrophenol is also an acidic compound, although it is weaker than benzene sulfonic acid. When it reacts with sodium bicarbonate, it will yield sodium para-nitrophenolate (C₆H₄(NO₂)O⁻Na⁺), water (H₂O), and carbon dioxide (CO₂).
- The reaction can be written as:
\[ C₆H₄(NO₂)OH + NaHCO₃ \rightarrow C₆H₄(NO₂)O⁻Na⁺ + H₂O + CO₂ \]

4. **Identify the Gases Released**:
- In both reactions, carbon dioxide (CO₂) is released as a gas.
- Therefore, the gases released when benzene sulfonic acid and para-nitrophenol are treated with NaHCO₃ are both CO₂.

5. **Final Answer**:
- The gases released, respectively, are CO₂ and CO₂.