Question

Which of the following is disproportionation reaction?

• A. Complete hydrolysis of $\text{XeF}_6$
• B. Complete hydrolysis of $\text{XeF}_4$
• C. Complete hydrolysis of $\text{XeF}_2$
• D. Partial hydrolysis of $\text{XeF}_6$

Hint:

$\text{XeF}_2$ undergoing hydrolysis behaves as a reducing agent, $\text{XeF}_6$ undergoes non-redox reactions, and $\text{XeF}_4$ is the only one that disproportionates.
This is an important distinguishing reaction of xenon tetrafluoride.

Answer 1

The Correct Option is B

Step 1: Keep the definition in mind.
Disproportionation means the same element ends up both oxidised and reduced in one reaction.
Step 2: Check complete hydrolysis of $\text{XeF}_6$.
\[ \text{XeF}_6 + 3\text{H}_2\text{O} \rightarrow \text{XeO}_3 + 6\text{HF} \] Xe stays at +6 the whole way through, no redox happening at all.
Step 3: Check complete hydrolysis of $\text{XeF}_4$.
This gives a mix of Xe(0) and Xe(+6) as $\text{XeO}_3$, the same starting element splitting into both a reduced and an oxidised product, textbook disproportionation.
Step 4: Check $\text{XeF}_2$ hydrolysis for contrast.
Here Xe simply drops from +2 to 0, a plain single reduction, not disproportionation.
Final answer: Option 2, complete hydrolysis of $\text{XeF}_4$.