When H2S has is passed through an orange red solution (X), the solution turns milky.

When H2S has is passed through an orange red solution (X), the solution turns milky. When an alkali is added to this orange red solution it turns yellow and on acidifying this yellow solution again turns orange red. X is

Answer

K2 Cr2O7 + 4H2SO4 +3 H2S = K2SO4+ Cr2(SO4)3+ 7H2O +3S

S forms colloid which give milky appearance and hides green color of Cr3+ ion

K2Cr2O7 (X) + KOH = K2CrO4 ( Not balanced )

orange red yellow

K2CrO4 + H2SO4 = K2Cr2O7 (X) ( Not balanced )