The process in which Cl₂ is obtained as a by-product is :

1.	In the electrolysis of aqueous HCl, Cl2 is obtained at the cathode as a by-product.
2.	In the electrolysis of aqueous NaCl, Cl2 is obtained at the cathode as a by-product.
3.	In the electrolysis of molten NaCl, Cl2 is obtained at the anode as a by-product.
4.	None of the above

Al can reduce MgO under the following conditions:

1. Above 500 °C, Al can reduce MgO

2. Below 500 °C, Al can reduce MgO

3. Below 1350 °C, Al can reduce MgO

4. Above 1350 °C, Al can reduce MgO

Consider the following statements:

Select the correct statements.

1. a, c, d

2. a, b

3. b, c

4. a, b, c, d

The chemical reactions taking place in the extraction of zinc from zinc blende is

1. $2\mathrm{ZnS}+3{\mathrm{O}}_2\to 2\mathrm{ZnO} + 2{\mathrm{SO}}_2$

2. $\mathrm{ZnO} + \mathrm{C}\stackrel{1673 \mathrm{K}}{\to }\mathrm{Zn} + \mathrm{CO}$

3. Both 1 and 2

4. None of the above

The reaction that do not take place in the blast furnace during the extraction of iron is-

1. Fe₂O_3(s) + 3CO_(g) → 2Fe₃O_4(s) + 3CO_2(g)

2. FeO_(s) + CO_(g) → Fe_(s) + CO_2(g)

3. 2 C_(s) + O_2(g) → 2 CO_(g)

4. None of the above

Incorrect statement(s) among the following options is/are:

The thermodynamic property useful for selecting the reducing agent is:

1. Gibbs free energy change .

2. Internal energy change.

3. Specific heat capacity.

4. None of the above.

Vapour phase refining process is used for refining :

1. Ni

2. Ti

3. Zr

4. All of the above

The incorrect statement(s)among the following is/are:

The better reducing agent for ZnO is: 

1. C

2. CO

3. CO₂

4. ${\mathrm{CO}}_3^{2-}$