Which of the following compounds could liberate `CO_(2)` with aqueous `NaHCO_(3)`?

Options

A.
B.
C.
D.

Answer

To determine which compounds can liberate CO₂ when reacted with aqueous NaHCO₃, we need to identify if the compounds have acidic protons. The reaction of NaHCO₃ with an acid (or a compound with an acidic proton) produces a sodium salt and releases carbon dioxide gas (CO₂). Let's analyze each option step by step.

### Step-by-Step Solution:

1. **Identify the Compounds**: We have four compounds to analyze. We need to check each one for the presence of acidic protons.

2. **Option 1**:
- The compound has an -OH group attached to a carbon chain with three nitro groups.
- The hydrogen in the -OH group is acidic because it is attached to an electronegative oxygen atom.
- The presence of three nitro groups (which are electron-withdrawing) increases the acidity of this proton due to their -I and -M effects.
- Therefore, this compound can react with NaHCO₃ to release CO₂.
- **Conclusion**: Option 1 can liberate CO₂.

3. **Option 2**:
- This compound also has an -OH group but is substituted with three -OCH₃ (methoxy) groups.
- The -OCH₃ groups have lone pairs that donate electron density to the ring, exhibiting a +M effect.
- This increases the electron density and decreases the acidity of the -OH proton, making it less likely to be released.
- Therefore, this compound cannot react with NaHCO₃ to release CO₂.
- **Conclusion**: Option 2 cannot liberate CO₂.

4. **Option 3**:
- The compound has a carbonyl group (C=O) adjacent to a CH₂ group.
- The hydrogen atoms in the CH₂ group are not acidic enough to react with NaHCO₃, as they do not have a highly electronegative atom (like oxygen) to stabilize the negative charge after deprotonation.
- Therefore, this compound cannot react with NaHCO₃ to release CO₂.
- **Conclusion**: Option 3 cannot liberate CO₂.

5. **Option 4**:
- This compound has a -SO₃H (sulfonic acid) group.
- The hydrogen in the -SO₃H group is highly acidic due to the stability of the conjugate base formed after deprotonation, which can be stabilized by resonance.
- Therefore, this compound can react with NaHCO₃ to release CO₂.
- **Conclusion**: Option 4 can liberate CO₂.

### Final Answer:
The compounds that can liberate CO₂ with aqueous NaHCO₃ are **Option 1 and Option 4**.