Gas released during roasting of sulphide ores.

Sulphide ore is

An amorphous soild A burns in air to form a gas B which turns lime water milky. The gas is also produced as a by - product during roasting of sulohide ore. This gas decolourises acidified aqueous KMnO_(4) solution and reduces Fe^(3+) to Fe^(2+) . Identify the solid A and the gas B and write the reactions involved.

The gas obtained by roasting of sulphide ore is reacted with acidified potassium dichromate. A green colored compound 'X' is formed. The compound X can be :

Explain the following (a) Although Au is soluble in aqua-regia, Ag is not (b) Zinc and hot copper is used for recovery of Ag from the complex [Ag(CN)_(2)]^(-) (c) Aluminium metal is frequently used as a reducing agent for extraction of metal such as chromium manganese etc. (d) Partial roasting of sulphide ore is done in the metallurgy of copper.

Which of the following statements, about the advantage of roasting of sulphide ore before reduction is not true gt

Levigation is generally employed for concentration of sulphide ores.

Why partial roasting of sulphide ore is done in the metallurgy of copper ?

Choose the correct option the code regarding roasting process. (I) It is the process of heating the ore in air in a reverberatory furnace to obtain the oxide. (II) It is an exothermic process. (III) It is used for the concentration of sulphide ore. (Iv) It removes easily oxidisable volatile impurities present in the concentrated ore.

Froth flotation process used for the concentration of sulphide ore.

Froth floatation process used for the concentration of sulphide ore :