Intro Flux Leaching Roasting Calcination

Sulphide ores of metals are usually concentrated by the froth flotation process. Which one of the following sulphide ores offers an exception and is concentrated by chemical leaching?

1. Argentite

2. Galena

3. Copper pyrite

4. Sphalerite

Which of the following elements is present as an impurity to the maximum extent in the pig Iron?
1. Carbon
2. Silicon
3. Phosphorus
4. Manganese

Aluminium is extracted from alumina Al₂O₃ by electrolysis of a molten mixture of:

1. ${\mathrm{Al}}_2{\mathrm{O}}_3+\mathrm{HF}+{\mathrm{NaAlF}}_4$

2. ${\mathrm{Al}}_2{\mathrm{O}}_3+{\mathrm{CaF}}_2+{\mathrm{NaAlF}}_4$

3. ${\mathrm{Al}}_2{\mathrm{O}}_3+{\mathrm{Na}}_3{\mathrm{AlF}}_6+{\mathrm{CaF}}_2$

4. ${\mathrm{Al}}_2{\mathrm{O}}_3+\mathrm{KF}+{\mathrm{Na}}_3{\mathrm{AlF}}_6$

Which one of the following is a mineral of iron?

1. Malachite

2. Cassiterite

3. Pyrolusite

4. Magnetite

An interstitial compound among the following is:

1. Invar

2. Steel

3. Bell metal

4. Bronze

Roasting of sulphides gives the gas X as a by-product. This is a colourless gas with a choking smell of burnt sulphur and causes great damage to respiratory organs as a result of acid rain. Its aqueous solution is acidic and acts as an oxidizing agent and its acid has never been isolated. The gas X is:

1. SO₂

2. CO₂

3. SO₃

4. H₂S

Extraction of gold and silver involves leaching with CN^- ion. Silver is later recovered by:

1. Distillation

2. Zone refining

3. Displacement with Zn

4. Liquation

Which one is a malachite from the following?

1. CuCO₃.Cu(OH)₂

2. CuFeS₂

3. Cu(OH)₂

4. Fe₃O₄

Match List-I with List-II

List- I (ores)	List- II (Composition)
(a) Haematite	(i)
(b) Magnetite	(ii)
(c) Calamine	(iii)
(d) Kaolinite	(iv)

Choose the correct answer from the options given below:

	(a)	(b)	(c)	(d)
1.	(i)	(iii)	(ii)	(iv)
2.	(i)	(ii)	(iii)	(iv)
3.	(iii)	(i)	(ii)	(iv)
4.	(iii)	(i)	(iv)	(ii)