Which of the following is not a disproportionation reaction? o I. NH NO N O 2H O II.P 3NaOH 3H O P H — Redox Reactions and Volumetric Analysis Chemistry Question

💡 Solution & Explanation

# Solution: Identifying Non-Disproportionation Reactions A **disproportionation reaction** occurs when a single element in one oxidation state is simultaneously oxidized AND reduced, forming two different oxidation states. Let me analyze each reaction: ## I. $2NH_4NO_2 \rightarrow N_2 + 2H_2O$ - In $NH_4^+$: N is at $-3$ oxidation state - In $NO_2^-$: N is at $+3$ oxidation state - Products show N at $0$ (in $N_2$) - **This IS disproportionation** (N goes from both $-3$ and $+3$ to $0$) ## II. $P_4 + 3NaOH + 3H_2O \rightarrow 3NaH_2PO_2 + PH_3$ - In $P_4$: P is at $0$ oxidation state - Products: - In $H_2PO_2^-$: P is at $+1$ - In $PH_3$: P is at $-3$ - **This IS disproportionation** (P at $0$ goes to both $+1$ and $-3$) ## III. $PCl_5 \rightarrow PCl_3 + Cl_2$ - In $PCl_5$: P is at $+5$, Cl is at $-1$ - Products: - In $PCl_3$: P is at $+3$, Cl is at $-1$ - In $Cl_2$: Cl is at $0$ - Only **Cl changes**: from $-1$ to both $-1$ and $0$ - **This IS disproportionation** (Cl disproportionates) ## IV. $IO_3^- + 5I^- + 6H^+ \rightarrow 3I_2 + 3H_2O$ - In $