The bond energy of B-F bond in ${\mathrm{BF}}_3$ is 646 kJ ${\mathrm{mol}}^{-1}$, while that of N-F bond in ${\mathrm{NF}}_3$ is 280 kJ ${\mathrm{mol}}^{-1}$. This is because

1.  N is more electronegative than B

2.  The atomic mass of N is higher than that of B

3.  The B-F bond gets a partial double bond character due to p-p overlap

4.  N has a lone pair of electrons while B does not have

 

 

The hybridization of boron in the stable borane having the lowest molecular weight is

1.  $s{p}^2$

2.  $s{p}^3$

3.  sp

4.  $s{p}^3$d

Identify the cyclic silicates ion given in the figure below

1.  ${\left[S{i}_4{O}_{25}\right]}^{24-}$

2.  ${\left[S{i}_6{O}_{18}\right]}^{12-}$

3.  ${\left[S{i}_4{O}_{12}\right]}^{12-}$

4.  ${\left[S{i}_6{O}_{24}\right]}^{12-}$

Which of the following oxides is acidic in nature?

1.  ${\mathrm{B}}_2{\mathrm{O}}_3$

2.  ${\mathrm{Al}}_2{\mathrm{O}}_3$

3.  ${\mathrm{Ga}}_2{\mathrm{O}}_3$

4.  ${\mathrm{In}}_2{\mathrm{O}}_3$

Catenation i.e., linking of similar atoms depends on size and electronic configuration of atoms. The tendency of catenation in Group 14 elements follows the order:

1.  C > Si > Ge > Sn

2.  C >> Si > Ge ≈ Sn

3.  Si > C > Sn > Ge

4.  Ge > Sn > Si > C

Silicon has a strong tendency to form polymers like silicones. The chain length of the silicone polymer can be controlled by adding

1.  ${\mathrm{MeSiCl}}_3$

2.  ${\mathrm{Me}}_2{\mathrm{SiCl}}_2$

3.  ${\mathrm{Me}}_3\mathrm{SiCl}$

4.  ${\mathrm{Me}}_4\mathrm{Si}$

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

1.  B > Al > Ga > In > Tl

2.  B < Al < Ga < In < Tl

3.  B < Al > Ga < In > Tl

4.  B > Al < Ga > In < Tl

In the structure of diborane

1.  All hydrogen atoms lie in one plane and boron atoms lie in a plane perpendicular to this plane.

2.  2 boron atoms and 4 terminal hydrogen atoms lie in the same plane and 2 bridging hydrogen atoms lie in the perpendicular plane.

3.  4 bridging hydrogen atoms and boron atoms lie in one plane and two terminal hydrogen atoms lie in a plane perpendicular to this plane.

4.  All the atoms are in the same plane.

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 aluminum hydride. The compounds X and Y are represented by the formulas.

1.  ${\mathrm{B}}_2{\mathrm{H}}_6, {\mathrm{B}}_3{\mathrm{N}}_3{\mathrm{H}}_6$

2.  ${\mathrm{B}}_2{\mathrm{O}}_3, {\mathrm{B}}_3{\mathrm{N}}_3{\mathrm{H}}_6$

3.  ${\mathrm{BF}}_3, {\mathrm{B}}_3{\mathrm{N}}_3{\mathrm{H}}_6$

4.  ${\mathrm{B}}_3{\mathrm{N}}_3{\mathrm{H}}_6, {\mathrm{B}}_2{\mathrm{H}}_6$

Quartz, widely employed as a piezoelectric material, contains the element:
1.  Pb
2.  Si
3.  Ti
4.  Sn