When picric acid is treated with aqueous sodium bicarbonate `(NaHoverset(14)(C)O_(3))` a gas is liberated with effervessence. The gas evolved would be :

Options

A. `H_(2)`
B. `CO_(2)`
C. `""^(14)CO_(2)`
D. `NO_(2)`

Answer

To determine the gas evolved when picric acid reacts with aqueous sodium bicarbonate (NaHCO₃), we can follow these steps:

### Step 1: Identify the Reactants
- **Picric Acid**: The chemical structure of picric acid is 2,4,6-trinitrophenol (C₆H₃N₃O₇). It is a strong acid due to the presence of the hydroxyl (-OH) group attached to a benzene ring.
- **Sodium Bicarbonate (NaHCO₃)**: This is a weak base that can react with acids to produce carbon dioxide (CO₂), water (H₂O), and a salt.

### Step 2: Write the Reaction
When picric acid reacts with sodium bicarbonate, the acidic hydrogen from picric acid reacts with the bicarbonate ion (HCO₃⁻) from sodium bicarbonate. The reaction can be represented as follows:

\[ \text{C}_6\text{H}_3\text{N}_3\text{O}_7 + \text{NaHCO}_3 \rightarrow \text{C}_6\text{H}_3\text{N}_3\text{O}_7\text{Na} + \text{H}_2\text{O} + \text{CO}_2 \uparrow \]

### Step 3: Analyze the Products
- The reaction produces a sodium salt of picric acid (sodium picrate), water (H₂O), and carbon dioxide (CO₂).
- The effervescence observed during the reaction is due to the release of carbon dioxide gas.

### Step 4: Conclusion
The gas evolved during the reaction of picric acid with aqueous sodium bicarbonate is carbon dioxide (CO₂).

### Final Answer
The gas evolved would be **carbon dioxide (CO₂)**.

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