Potassium dichromate is prepared from

Options

A. chromate obtined by the fusion of chromite ore with sodium carbonate in free access of air
B. pyrolusite which is fused with potassium hydroxide in th presence of air
C. iron pyrites by the fusion with potassium carbonate in presence of moisture
D. none of these

Answer

A

Explanation

`underset("Chromite ore")(4FeCr_2O_4)+8Na_2Xo_3+7O_2tounderset("(yellow)")underset("Sodium chriomate")(8Na_2CrO_4)+2Fe_2O_3+8CO_2`
`2Na_2CrO_4+2H^(+)toNa_2Cr_2O_7+2Na^(+)+H_2O`
`Na_2Cr_2O_7+2HCI to underset("dichromate")underset("Potassium")(K_2Cr_2O_7)+2NaCl`