The Reaction
When fluorine gas (F₂) is bubbled through a solution of sodium bromide (NaBr), a single displacement reaction occurs. Fluorine, being a more reactive halogen than bromine, displaces bromine from the bromide ions:
F₂ (g) + 2 NaBr (aq) → Br₂ (l) + 2 NaF (aq)
Explanation
* Fluorine (F₂): Fluorine is the most reactive element on the periodic table. It readily gains electrons to achieve a stable electron configuration.
* Sodium bromide (NaBr): This is a soluble ionic compound. In solution, it exists as sodium ions (Na⁺) and bromide ions (Br⁻).
* Bromine (Br₂): Bromine is a reddish-brown liquid at room temperature.
* Sodium fluoride (NaF): This is also a soluble ionic compound and remains dissolved in the solution.
The Products
* Free Bromine (Br₂): This is the liquid product you observe. It's the displaced bromine, which is less reactive than fluorine.
* Fluoride (F⁻) in solution: The fluoride ions produced remain dissolved in the solution as part of the sodium fluoride (NaF).
Key Point: The reaction is driven by the difference in reactivity between fluorine and bromine. Fluorine is more electronegative and thus has a stronger pull on electrons, causing it to displace bromine from the bromide ions.
