Question

Consider the change in oxidation state of Bromine corresponding to different emf values as

shown in the diagram below



Then the species undergoing disproportionation is

• A. $Br_{2}$
• B. $BrO_{4}^{-}$
• C. $BrO_{3}^{-}$
• D. HBrO

Answer 1

Answer: (D)

$\overset{+ 1}{H B r O} \rightarrow \overset{0}{B r_{2}},E_{H B r O / B r_{2}}^{0}=1.595V$

$\overset{+ 1}{H B r O} \rightarrow \overset{+ 5}{B r}O_{3}^{-},E_{B r O_{3}^{-} / H B r O}^{0}=1.5V$

$E_{c e l l}^{0}$ for the disproportionation of HBrO,

$E_{c e l l}^{0}=E_{H B r O / B r_{2}}^{0}-E_{B r O_{3}^{-} / H B r O}^{0}$

$=1.595-1.5=0.095V=+ve$