Question

How is potassium dischromate prepared from chrome iron?

Answer 1

(1)Potassium dichromate(K2Cr2O7) is prepared from chromite ore FeCr2O4. ... The yellow solution of sodiumchromate is filtered and acidified with sulfuric acid to give a solution from which orange sodium dichromate , Na2Cr2O7 2H2O can be crystallized.

Answer 2

Answer:

Preparation of potassium dichromate

Explanation:

( FeCr2O4 )

• chromite ores is reacted with either , sodium carbonate or potassium carbonate
• The condition for this is the availability of excess oxygen.
• From this we acquire  (Na2CrO4)  sodium chromate .
• This is the balanced formulate for the reaction
• 4FeCr2O4 + 8Na2CO3 + 7O2 —> 8Na2CrO4 + 2FeO3 + 8CO2
• After this the product is filtered to remove all the remaining foreign material.
• Later it is reacted with sulphuric acid which produces the sodium dichromate solution .
• 2NaCrO4 + 2H+ (from H2SO4 ) → Na2Cr2O7 + 2Na + H2O
• Finaly it is reacted with any potassium compound , this is due to the solubility of sodium dichromate that supersedes the solubility of potassium dichromate .