See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Solution **Step 1: Reaction of Benzenesulfonic Acid with $NaHCO_3$** Benzenesulfonic acid ($C_6H_5SO_3H$) is a strong acid. When treated with $NaHCO_3$ (a weak base): $$C_6H_5SO_3H + NaHCO_3 \rightarrow C_6H_5SO_3Na + H_2O + CO_2 \uparrow$$ The $HCO_3^-$ ion decomposes, releasing $\boxed{CO_2}$ gas. **Step 2: Reaction of p-Nitrophenol with $NaHCO_3$** p-Nitrophenol ($4-NO_2-C_6H_4OH$) is a **weak acid** (due to electron-withdrawing $NO_2$ group): $$4-NO_2-C_6H_4OH + NaHCO_3 \rightarrow 4-NO_2-C_6H_4ONa + H_2O + CO_2 \uparrow$$ The weak acid donates a proton to $HCO_3^-$, which decomposes to release $\boxed{CO_2}$ gas. **Key Point:** $NaHCO_3$ is weak enough to deprotonate weak acids like phenols, but strong $NaOH$ would be needed for stronger deprotonation. The weak base shifts equilibrium, allowing both acids to release $CO_2$. **Answer: (D) $CO_2$, $CO_2$** ✓