Write the balanced equations in the manufacture of potassium dichromate from chromite ore.

Explanation

1. `4FeOCr_(2)O_(3) + 8Na_(2)CO_(3) + 7O_(2) rarr 8Na_(2)CrO_(4) + 2Fe_(2)O_(3) + 8CO_(2) uarr`
2. `2Na_(2)CrO_(4) + 2H^(+) rarr Na_(2)Cr_(2)O_(7) + 2Na^(+) + H_(2)O`
or
`2Na_(2)CrO_(4) + H_(2)SO_(4) rarr Na_(2)Cr_(2)O_(7) + Na_(2)SO_(4) + H_(2)O`
3. `Na_(2)Cr_(2)O_(7) + 2KCl rarr K_(2)Cr_(2)O_(7) + 2NaCl`
equation for manufacture of potassium dichromate from chromite ore :
(i) Conversion of chromite into sodium chromate :
`underset("(Chromite ore)")(4FeO.Cr_(2)O_(3)) + 8Na_(2)CO_(3) + 7O_(2) rarr underset("(Sodium chromate)")(8Na_(2)CrO_(4)) + 2Fe_(2)O_(3) + 9CO_(2)`
(ii) Conversion of sodium chromate into sodium dichromate :
`underset("(Sodium chromate)")(2Na_(2)CrO_(4))+H_(2)SO_(4) rarr underset("(Sodium dichromate)")(Na_(2)Cr_(2)O_(7)) + Na_(2)SO_(4)+H_(2)O`
(iii) Conversion of sodium dichromate into potassium dichromate :
`Na_(2)cr_(2)O_(7) + 2KCl rarr underset("(Potassium dichromate)")(K_(2)Cr_(2)O_(7)) + 2NaCl`