Hydrogen will not reduce 

1. heated cupric oxide

2. heated ferric oxide

3. heated stannic oxide

4. heated aluminium oxide

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

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 oxide is amphoteric in nature?

1. SnO₂

2. SiO₂

3. GeO₂

4. CO₂

Which of the following statements is incorrect?