Question

the bromate reacts with iron(ii) ions, forming bromide ions and iron(iii) ions in an acidic solution.\\(\ce{bro^-_{3} + fe^{2+} \
ightarrow br^- + fe^{3+}}\\)\
which component is going through reduction?\
a. \\(\ce{bro^-_{3}}\\)\
\quad\quad b. \\(\ce{fe^{2+}}\\)\
enter the answer choice letter.

Explanation:

Reduction is gain of electrons (or decrease in oxidation state). For $\ce{BrO^{-}_{3}}$: Br in $\ce{BrO^{-}_{3}}$ has oxidation state +5 (let Br's oxidation state be $x$, $x + 3(-2)= -1\Rightarrow x = +5$). In $\ce{Br^-}$, Br has oxidation state -1 (decrease, so reduction). For $\ce{Fe^{2+}}$: Fe goes from +2 to +3 in $\ce{Fe^{3+}}$ (increase, oxidation). So $\ce{BrO^{-}_{3}}$ is reduced.

Answer:

A. $\ce{BrO^{-}_{3}}$