Your Blood turns Green

Acidified K_2Cr_2O_7 solution turns green when sodium sulphite is added to it. Explain.

Acidified K_(2)Cr_(2)O_(7) solution turns green when NasO_(3) is added to it. This is due to the formation of :

Fe(OH)_(2) is precipitated from Fe(II) solutions as a while solid turns dark green and then brown due to the formation of:

A gas when passed through K_(2)Cr_(2)O_(7) and dil. H_(2)SO_(4) solution turns it green, the gas is :

Acidified K_(2)Cr_(2)O_(7) , solution turns green when Na_(2)SO_(3) is added to it. Thus is due to the formation of