A mixed oxide of iron and chromium is fused with sodium carbonate in free access of air to from a yellow, coloured compound (A). On acidification the compounf (A) froms an orange coloured compound (B), which is a strong oxidizing agent. Identify compound (A) and (B). Write chemical reactions involved.

Explanation

`underset(("ore"))underset("Chromite")(4FeO. Cr_(2))O_(3)+underset("Carbonate")underset("Sodium")(8Na_(2))CO_(3)+7Oto underset(("Yellow"))underset((A))underset("Sodium Chromate")(8Na_(2)CrO_(4)+2Fe_(2))O_(3)+8CO_(2)`