Chemistry - Salt Analysis Question with Solution | TestHub

A mixture contains a Reddish Brown metallic oxide (A) and a yellow crystalline salt (B). When the mixture is treated with dilute sulphuric acid, it yields a clear acidic filtrate along with a yellow insoluble residue (B). The filtrate is oxidised with excess hydrogen peroxide, and the solution is subsequently boiled to expel the excess peroxide, cooled, and then divided into two equal portions.

(C). The first portion, on treatment with aqueous potassium ferrocyanide solution , produces a blue precipitate

• The second portion, on addition of ammonium thiocyanate ,develops a blood-red coloration.

The insoluble residue (B) is found to be :

• Insoluble in excess aqueous ammonia ,

• But readily soluble in potassium cyanide solution as well as in sodium thiosulphate solution.

Furthermore, the sodium extract of the original mixture, when treated with chlorine water, yields a brown solution. On shaking this solution with chloroform, the organic layer turns violet.