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

Find the solubility product (Kₛₚ) of Ba(OH)₂ if the pH of its saturated solution is 12.

The change in oxidation number of chlorine when Cl₂ gas reacts with hot and concentrated sodium hydroxide solution is:

1. Zero to +1 and Zero to –5

2. Zero to –1 and Zero to +5

3. Zero to –1 and Zero to +3

4. Zero to +1 and Zero to –3

Maximum number of electrons in a subshell with l = 3 and n = 4 is:

1. 14

2. 16

3. 10

4. 12

Which one of the following is an outer orbital complex and exhibits paramagnetic behavior?

1. $\left[Ni\right(N{H}_3{)}_6{]}^{2+}$

2. $\left[Zn\right(N{H}_3{)}_6{]}^{2+}$

3. $\left[Cr\right(N{H}_3{)}_6{]}^{3+}$

4. $\left[Co\right(N{H}_3{)}_6{]}^{3+}$

In a reaction, A + B → Product, the rate is doubled when the concentration of B is doubled, and the rate increases by a factor of 8, when the concentrations of both the reactants (A and B) are doubled. The rate law for the reaction can be written as:

1. Rate = k[A][B]²

2. Rate = k[A]²[B]²

3. Rate = k[A][B]

4. Rate = k[A]²[B]

In which of the following reactions, the standard reaction entropy change
$(∆S^0)$ is positive, and standard Gibb's energy change
$(∆G^0)$ decreases sharply with increasing temperature?

Which one of the following is a mineral of iron?

1. Malachite

2. Cassiterite

3. Pyrolusite

4. Magnetite

In the Freundlich adsorption isotherm, the value of 1/n is:
1. Between 0 and 1 in all cases.
2. Between 2 and 4 in all cases.
3. 1 in the case of physical adsorption.
4. 1 in the case of chemisorption.

Which of the following equimolar solutions, prepared separately, will have the highest pH?