b) Sulfur dioxide làm mất màu dung dịch bromine: SO2 + Br2 + H2O → HBr + H2SO4

Trả lời

b) $\stackrel{+4}{S}{O}_2+{\stackrel{0}{Br}}_2+H_{2}O\to H\stackrel{-1}{Br}+H_2\stackrel{+6}{S}{O}_4$

Ta có:

$\begin{array}{c}1\times \\ 1\times \end{array}\left|\begin{array}{l}\stackrel{+4}{S}\to \stackrel{+6}{S}+2e\\ {\stackrel{0}{Br}}_2+2e\to 2\stackrel{-1}{Br}\end{array}\right.$

Vậy SO₂ + Br₂ + 2H₂O → 2HBr + H₂SO₄