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

Explanation

Manufacture of potassium dichromate `(k_(2)Cr_(2)O_(7))` from chromate ore `(FeCr_(2)O_(4))` by the following steps.
Step I : Chromate ore is heated with sodium carbonate in excess of air to form sodium chromate.
`4FeCr_(2)O_(4)+8Na_(2)CO_(3)+7O_(2)rarrSNa_(2)CrO_(4)+2Fe_(2)O_(3)+8CO_(2)`
Step II : The yellow solution of sodium chromate is filtered and acidified with sulphuric acid to give orange solution of rod dictromate.
`2Na_(2)CrO_(4)+H_(2)SO_(4)rarrNa_(2)Cr_(2)O_(7)+Na_(2)SO_(4)+H_(2)O`
the less soluble sodium sulphate removed by filtration.
Step III : The solution of sodium dictromate is treated with kcl to form potassium dicromate.
`Na_(2)Cr_(2)O_(7)+2KClrarr k_(2)Cr_(2)O_(7)+2NaCl`