Question

Which one of the following statements is correct when $S{O}_2$ is passed through acidified $K_{2}C{r}_2{O}_7$ solution?

• A. The solution is decolourized.
• B. $S{O}_2$ is reduced.
• C. Green $C{r}_2(S{O}_4{)}_3$ is formed.
• D. The solution turns blue.

Answer 1

The correct option is C

Green $C{r}_2(S{O}_4{)}_3$ is formed.

$S{O}_2$ is oxidised to $S{O}_4^{2-}$ when passed through acidified $K_{2}C{r}_2{O}_7$ solution, Cr(VI) gets reduced to Cr(III) which forms a green coloured compound.