To an acidified dichromate solution, a pinch of `Na_(2)O_(2)` is added and shaken. What is observed ?

Options

A. Blue colour
B. Orange colour changing to green
C. Copious evolution of oxygen
D. Bluish-green precipitate

Answer

A, C

Explanation

`underset("orange")(Cr_(2)O_(7)^(2-))+10H^(+)+2Na_(2)O_(2) to (##BLJ_VKJ_ORG_CHE_C08_E04_013_S01##) +8Na^(+)+5H_(2)O`
In the absence of ether or amyl alcohol, `CrO_(3)` in acidic medium decomposes to `Cr^(3+)` with evolution of oxygen.