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[Зюня]

Cr=>[Cr(H2O)6](3 )=>Cr2O7(2-)=>CrO4(2-)=>[Cr(H2O)6](3 ) написать реакции.

[chernyubarsik]

\( a)4Cr+12HCl+3{O}_{2}+18{H}_{2}O\rightarrow 4\left[Cr\left({H}_{2}O \right)_{6} \right]{Cl}_{3} \)

\( b)2\left[Cr\left({H}_{2}O \right)_{6} \right]{Cl}_{3}+NaCl{O}_{3}\rightarrow NaCl+{H}_{2}{Cr}_{2}{O}_{7}+6HCl

+8{H}_{2}O \)

\( c){H}_{2}{Cr}_{2}{O}_{7}+4KOH\rightarrow 2{K}_{2}Cr{O}_{4}+3{H}_{2}O \)

\( d)2{K}_{2}Cr{O}_{4}+{H}_{2}S{O}_{4}\rightarrow {K}_{2}{Cr}_{2}{O}_{7}+{K}_{2}S{O}_{4}+{H}_{2}O \)

\( e){K}_{2}{Cr}_{2}{O}_{7}+6KI+7{H}_{2}S{O}_{4}+5{H}_{2}O\rightarrow \left[ Cr\left( {H}_{2}O\right)_{6}\right]_{2}\left( S{O}_{4}\right)_{3}+4{K}_{2}S{O}_{4}+3{I}_{2} \)