Step 1: Understanding the Concept:
This refers to Karl Christe's chemical synthesis of fluorine (1986). Usually, \(F_{2}\) is prepared by electrolysis, but it can be prepared chemically using a strong Lewis acid to displace a weaker Lewis acid.
Step 2: Key Formula or Approach:
The reaction involves displacement of unstable \(MnF_{4}\) from its salt by \(SbF_{5}\).
: Detailed Explanation:
1. \(SbF_{5}\) is a much stronger Lewis acid than \(MnF_{4}\).
2. When \(K_{2}MnF_{6}\) reacts with \(SbF_{5}\), the antimony fluoride displaces manganese tetrafluoride:
\[ K_{2}MnF_{6} + 2SbF_{5} \rightarrow 2KSbF_{6} + MnF_{4} \]
3. Manganese tetrafluoride (\(MnF_{4}\)) is thermodynamically unstable and spontaneously decomposes into manganese trifluoride and fluorine gas:
\[ 2MnF_{4} \rightarrow 2MnF_{3} + F_{2}(g) \]
The overall combined reaction is:
\[ 2K_{2}MnF_{6} + 4SbF_{5} \rightarrow 4KSbF_{6} + 2MnF_{3} + F_{2} \]
Step 3: Final Answer:
The reagent used is \(SbF_{5}\).