Match the items in Column I with the items in Column II and assign the correct code.

Codes

Among the following an iron mineral is:

1. Malachite

2. Cassiterite

3. Pyrolusite

4. Magnetite

Roasting of sulphides gives the gas 'X' as a by-product. This is a colourless gas with the 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 an oxidising agent, and its acid has never been isolated. The gas 'X' is:

1. SO₂

2. CO₂

3. SO₃

4. H₂S

From the following, the ores that are concentrated by froth flotation are:

Choose the correct option:
1. a and b
2. b and c
3. c and d
4. a and d

The fundamental principle of froth flotation process is:

Which are the most abundant elements present inside the earth's crust?

1. Al, and Fe 

2. Al, and Cu

3. Fe, and Cu

4. Cu, and Ag

The chemical composition of "slag" formed during the smelting process in the extraction of copper is:

1. Cu₂ + FeS                                    

2. FeSiO₃

3. CuFeS                                         

4. Cu₂S + FeO

Consider the following reaction.
\(\small{Bauxite\ ore\ +\ NaOH\ (conc.) \xrightarrow[\Delta]{Digester} \underset{Soluble}{(A)}}\)
\((A) \xrightarrow{Fresh\ Al(OH)_3}\ \underset{White}{(B)}\ +\ (C)\)
\({(B)} \xrightarrow[]{\Delta}\ (D)\ +\ H_2O\)
What is the molecular formula of compound D?

1. ${\mathrm{NaAlO}}_2$

2. $\mathrm{Al}{\left(\mathrm{OH}\right)}_3$

3. ${\mathrm{Al}}_2{\mathrm{O}}_3$

4. ${\mathrm{Na}}_2\mathrm{O}$

Reactions among the following that occur during calcination are:

Choose the correct option:
1. a and b
2. b and c
3. c and d
4. a and c

The substance that acts as a collector in the froth flotation method is:

1. Sodium xenate.           

2. Sodium pyrophosphate.

3. Sodium nitroprusside.

4. Sodium ethyl xanthate.