Sulphide ores of metals are usually concentrated by froth flotation process. Which one of the following sulphide ores offers an exception and is concentrated by chemical leaching?
3. Copper pyrite
A pair of metals that can be purified by van Arkel method is:
1. Zr and Ti
2. Ag and Au
3. Ni and Fe
4. Ga and In
Which of the following elements is present as an impurity to the maximum extent in the pig Iron?
An interstitial compound among the following is -
3. Bell metal
In the extraction of copper from its sulphide ore, the metal is finally obtained by the reduction of cuprous oxide with
1. Copper(l) sulphide (Cu2S)
2. Sulphur dioxide (SO2)
3. Iron Sulphide (FeS)
4. Carbon monoxide (CO)
Which one of the following is a mineral of iron?
Aluminium is extracted from alumina Al2O3 by electrolysis of a molten mixture of:
Roasting of sulphides gives the gas X as a by-product. This is a colourless gas with choking smell of burnt sulphur and causes great damage to respiratory organs as a result of acid rain. Its aqueous solution is acidic, acts as a oxidizing agent and its acid has never been isolated. The gas X is:
"Metals are usually not found as nitrates in their ores". Out of the following two (I and II)
The following reactions take place in the blast furnace in the preparation of impure iron.
Identify the reaction pertaining to the formation of the slag.
1. 2C(s) + O2(g) → 2CO (g)
2. Fe2O3(s) + 3CO (g) → 2Fe(l) + 3CO2(g)
3. CaCO3(s) → CaO(s) + CO2(g)
4. CaO(s) + SiO2(s) → CaSiO3(s)