The most volatile compound among the following is -

1.  ${\mathrm{CH}}_4$

2.  ${\mathrm{SiH}}_4$

3.  ${\mathrm{GeH}}_4$

4.  ${\mathrm{SnH}}_4$

The coordination number of Al in aluminates, is-

Select the correct statement(s) regarding the following reaction sequence:

 
   

1.  The compound (A) is ${\left({\mathrm{CH}}_3\right)}_2{\mathrm{SiCl}}_2$

2.  The compound D is SiC

3.  The compound (B) is ${\left({\mathrm{CH}}_3\right)}_2\mathrm{Si}{\left(\mathrm{OH}\right)}_2$

4.  All of the above

A species among the following that decomposes easily is: -

A strong oxidizing agent among the following is -

1.  ${\mathrm{Tl}}^{3+}$

2.  ${\mathrm{Ga}}^{3+}$

3.  ${\ln }^{3+}$

4.  ${\mathrm{Al}}^{3+}$

From the following, the compound(s) that react(s) with \(\mathrm{BF}_3\) is/are -

Ionization enthalpy (${∆}_{\mathrm{i}}{\mathrm{H}}_1\mathrm{kJ} {\mathrm{mol}}^{-1}$) for the elements of Group 13 follows the order.

A compound X, of boron, reacts with ${\mathrm{NH}}_3$ on heating to give another compound Y which is called inorganic benzene. The compound X can be prepared by treating ${\mathrm{BF}}_3$ with Lithium aluminium hydride. The compounds X and Y are represented by the formulas -

Carbon dioxide is a gas but silica is a solid because:

1. Carbon dioxide is composed of discrete covalent ${\mathrm{CO}}_2$ molecules whereas silica has a continuous tetrahedral structure.

2. ${\mathrm{CO}}_2$ molecules are lighter than ${\mathrm{SiO}}_2$ molecules.

3. ${\mathrm{CO}}_2$ is more acidic than ${\mathrm{SiO}}_2$.

4. The melting point of silica is very high.

In diborane, the two H-B-H angles are nearly-

1. $60°,$ $120°$

2. $97°,120°$

3. $97°,150°$

4. $120°,$ $180°$