`K_(2)Cr_(2)O_(7)` on heating with aqueous NaOH gives

H_(2)Cr_(2)O_(7) on heating with aqueous NaOH gives

K_(2)Cr_(2)O_(7) , on heating gives

(NH_(4))_(2)Cr_(2)O_7 on heating gives:

Acidified K_(2)Cr_(2)O_(7) on reaction with hydrogen peroxide give deep blue solution due to formation of