Which of the following is a Lewis acid?

1. ${\mathrm{AlCl}}_3$

2. ${\mathrm{MgCl}}_2$

3. ${\mathrm{CaCl}}_2$

4. ${\mathrm{BaCl}}_2$

The geometry of a complex species can be understood from the knowledge of the type of hybridization of orbitals of the central atom. The hybridization of orbitals of a central atom in ${\left[\mathrm{B}\right({\mathrm{OH}}_4\left)\right]}^{-}$ and the geometry of the complex are respectively

1. sp³, tetrahedral

2. sp³, square planar

3. sp³d², octahedral

4. dsp², square planar

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. ${\mathrm{In}}_2{\mathrm{O}}_3$

The exhibition of the highest coordination number depends on the availability of vacant orbitals in the central atom. Which of the following elements is not likely to act as a central atom in ${\mathrm{MF}}_6^{3-}$?

1. B

2. Al

3. Ga

4. In

Boric acid is an acid because its molecule

1. Contains replaceable H⁺ ion

2. Gives up a proton

3. Accepts OH^- from water releasing proton

4. Combines with proton from water molecule

Catenation i.e., linking of similar atoms depends on the size and electronic configuration of atoms. The

the tendency of catenation in group 14 elements follows the order-

1.  $\mathrm{C}>\mathrm{Si}>\mathrm{Ge}>\mathrm{Sn}$

2.  $\mathrm{C}>>\mathrm{Si}>\mathrm{Ge}\approx \mathrm{Sn}$

3.  $\mathrm{Si}>\mathrm{C}>\mathrm{Sn}>\mathrm{Ge}$

4.  $\mathrm{Ge}>\mathrm{Sn}>\mathrm{Si}>\mathrm{C}$

Silicon has a strong tendency to form polymers like silicones. The chain length of 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.  ${\mathrm{Me}}_4\mathrm{Si}$

The correct order of Ionization enthalpy $({∆}_{\mathrm{i}}\mathrm{H} \mathrm{kJ} {\mathrm{mol}}^{-1})$ for the elements of group 13 among the following is-

1.  B>Al>Ga>In>Tl

2.  B<Al<Ga<In<Tl

3.  $\mathrm{B}<\mathrm{Al}>\mathrm{Ga}<\mathrm{In}<\mathrm{Tl}$

4.  $\mathrm{B}>\mathrm{Al}<\mathrm{Ga}>\mathrm{In}<\mathrm{Tl}$

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

Identify the correct resonance structures of carbon dioxide from one given below

a.  ${}^{-}\mathrm{O}-\mathrm{C}={\mathrm{O}}^{+}$

b.  $\mathrm{O}=\mathrm{C}=\mathrm{O}$

c.  ${}^{-}\mathrm{O}\equiv \mathrm{C}-{\mathrm{O}}^{+}$

d.  ${}^{-}\mathrm{O}-\mathrm{C}\equiv {\mathrm{O}}^{+}$

Choose the correct option:

1. (a, b)

2. (b, c)

3. (c, d)

4. (b, d)