Kemija - 2022. ljeto, 20.

A. $\mathrm{I}_{2}+2 ~\mathrm{e}^{-} \rightarrow 2 ~\mathrm{I}^{-}$

B. $2 ~\mathrm{I}^{-} \rightarrow \mathrm{I}_{2}+2 ~\mathrm{e}^{-}$

C. $\mathrm{SO}_{3}{ }^{2-}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{SO}_{4}{ }^{2-}+2 ~\mathrm{H}^{+}+2 ~\mathrm{e}^{-}$

D. ${\mathrm{S}\mathrm{O}}_4{}^{2-}+2{\mathrm{H}}^{+}+2{\mathrm{e}}^{-}\to {\mathrm{S}\mathrm{O}}_3{}^{2-}+{\mathrm{H}}_2\mathrm{O}\backslash mathrm\{SO\}\_\{4\}\{\; \}^\{2-\}+2\; ~\backslash mathrm\{H\}^\{+\}+2\; ~\backslash mathrm\{e\}^\{-\}\; \backslash rightarrow\; \backslash mathrm\{SO\}\_\{3\}\{\; \}^\{2-\}+\backslash mathrm\{H\}\_\{2\}\; \backslash mathrm\{O\}$