Question

Which reaction is not feasible :-

• A. $ 2KI + Br_2 \to 3KBr + I_2$
• B. $2KBr + I_2 \to 2KI + Br_2$
• C. $ 2KBr + CI_2 \to 2KCI + Br_2$
• D. $ 2H_2O + 2F_2 \to 4HF + O_2$

Answer 1

The Correct Option is B

To determine which reaction is not feasible, we need to analyze the reactions based on the tendency of halogens to act as oxidizing agents. A more electronegative halogen can displace a less electronegative halogen from its compounds. The order of reactivity as oxidizing agents for halogens is: Fluorine (F₂) > Chlorine (Cl₂) > Bromine (Br₂) > Iodine (I₂). 

1. Reaction Analysis:
   • \(2\text{KI} + \text{Br}_2 \to 2\text{KBr} + \text{I}_2\): Bromine is more reactive than iodine, so it can displace iodine from potassium iodide (KI), making this reaction feasible.
   • \(2\text{KBr} + \text{I}_2 \to 2\text{KI} + \text{Br}_2\): Iodine is less reactive than bromine, so it cannot displace bromine from potassium bromide (KBr). Therefore, this reaction is not feasible.
   • \(2\text{KBr} + \text{Cl}_2 \to 2\text{KCl} + \text{Br}_2\): Chlorine is more reactive than bromine, so it can displace bromine from potassium bromide (KBr), making this reaction feasible.
   • \(2\text{H}_2\text{O} + 2\text{F}_2 \to 4\text{HF} + \text{O}_2\): Fluorine is highly reactive and can oxidize water to produce hydrofluoric acid (HF) and oxygen. This reaction is feasible.
2. Conclusion:

Based on the reactivity of halogens, the reaction \(2\text{KBr} + \text{I}_2 \to 2\text{KI} + \text{Br}_2\) is not feasible, as iodine cannot displace bromine.