Give preparation of Potassium dichromate starting from chromite ore

CBSE Class 12
1

Give preparation of Potassium dichromate starting from chromite ore.

2

Potassium dichromate is prepared from chromite ore (FeCr2O4). This preparation involves many steps.
Preparation of sodium chromate
Chromite ore is finely powdered and is heated with sodium carbonate in the presence of air in a reverberatory furnace. This reaction produces sodium chromate.
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Conversion of sodium chromate into sodium dichromate
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The sodium chromate formed in the above reaction is treated with concentrated sulphuric acid to form sodium dichromate.
Sodium sulphate on cooling separates as Na2SO4.10H2O leaving sodium dichromate.
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Conversion of Sodium dichromate into potassium dichromate
The sodium dichromate formed above is treated with KCl to form potassium dichromate.
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