Give the preparation of `K_2Cr_2O_7` from chromite ore.

Write chemical reaction for preparation of K2Cr207 from chromite ore.

Give one method of Preparation of K_2Cr_2O_7 from sodium chromate.

Give one method of preparation of H_2O_2 .

Describe the preparation of potassium dichromate from iron chromite ore. What is the effect of increasing pH on a solution of potassium dichromate?

Write the reaction of SO_2 with K_2 Cr_2 O_7

Give the preparation of Potassium Permanganate from Pyrolusite ore.

Describe the reaction of acidified K_2Cr_2O_7 with the following: FeSO_4 solution

Describe the reaction of acidified K_2Cr_2O_7 with H_2S solution.