Chemistry · Group 13 to Group 18 Elements

Concentrated cannot be used to prepare HBr or HI from KBr or KI because it

Concentrated \( \boldsymbol{H}_{2} \boldsymbol{S} \boldsymbol{O}_{4} \) cannot be used to prepare HBr or HI from KBr or KI because it

  • A. reacts too slowly with KBr or KI
  • B. reduces HBr or H
  • C. oxidises KBror KI
  • D. oxidises KBr to \( K B r O_{3} \) or \( K \) I to \( K I O_{3} \)

Step-by-step solution

Concentrated H2SO4 is a strong oxidizing agent. It oxidizes Br⁻ to Br₂ and I⁻ to I₂, preventing the formation of HBr or HI. Instead, the halogens are produced as gases (Br₂, I₂) along with SO₂ and water.
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