Aluminium reacts with concentrated HCl and concentrated NaOH to liberate which of the following gases respectively-

1.	\(\mathrm{H}_2 ~\text{and} ~\mathrm{H}_2 \)	2.	\(\mathrm{O}_2 ~\text{and} ~\mathrm{O}_2 \)
3.	\(\mathrm{O}_2 ~\text{and} ~\mathrm{H}_2 \)	4.	\(\mathrm{H}_2 ~\text{and} ~\mathrm{O}_2 \)

Hydrogen will not reduce 

1. heated cupric oxide

2. heated ferric oxide

3. heated stannic oxide

4. heated aluminium oxide

The basic structural unit of silicates is-

When silicon is boiled with caustic soda solution, the gas is evolved is-

1. ${\mathrm{O}}_2$

2. ${\mathrm{SiH}}_4$

3. ${\mathrm{H}}_2$

4. None of the above

An anion that cannot be formed by Boron is -

1. ${\mathrm{BF}}_6^{3-}$

2. ${\mathrm{BH}}_4^{-}$

3. $\mathrm{B}{\left(\mathrm{OH}\right)}_4^{-}$

4. ${\mathrm{BO}}_2^{-}$

Identify the correct statements from the following:

${\mathrm{B}}_2{\mathrm{H}}_6$ can't be prepared by -

1. ${\mathrm{NaBH}}_4$ $$ $+$ ${\mathrm{I}}_2$ $\to$

2. ${\mathrm{BF}}_3$ $$ $+$ $\mathrm{NaH}$ $\to$

3. ${\mathrm{B}}_3{\mathrm{N}}_3{\mathrm{H}}_6$ $$ $+$ ${\mathrm{H}}_2\mathrm{O}$ $\to$

4. ${\mathrm{Mg}}_3{\mathrm{B}}_2$ $+$ $\mathrm{dil}$ $\mathrm{HCl}\to$

White fumes appear around the bottle of anhydrous AlCl₃. This is due to :

1. Formation of Al(OH)₃

2. Dimerisation of AlCl₃

3. Hydrolysis of AlCl₃ gives HCl gas

4. Adsorption of moisture 

Which of the following statements is incorrect?