Which of the following gas is least polarizable?

1.  He

2.  Ne

3.  Kr

4.  Xe

Which of the following is correct order of dipole moment of the following?

1.  I  > II > III

2.  I = II = III

3.  III > II > I

4.  I > III > II

For the ${\mathrm{PO}}_4^{3-}$ ion, what are the formal charges on each oxygen atom and the bond order of the P-O bond, respectively?

Carbon suboxide $\left({\mathrm{C}}_3{\mathrm{O}}_2\right)$ has

1.  Linear structure

2.  Bent structure

3.  Trigonal structure

4.  Distorted tetrahedral structure

The total number of $\mathrm{\pi }$-bond electrons in the following structure is

1.  4

2.  8

3.  12

4.  16

The state of hybridisation of 'B' atoms in borax $\left({\mathrm{Na}}_2{\mathrm{B}}_4{\mathrm{O}}_7<mspace\; width="1em"></mspace>·<mspace\; width="1em"></mspace>10{\mathrm{H}}_2\mathrm{O}\right)$ is

1.  All sp² hybridised

2.  Three sp² and one sp³ hybridised

3.  One sp² and three sp³ hybridised

4.  Two sp² and two sp³ hybridised

The number of $\mathrm{P}-\mathrm{O}-\mathrm{P}$ linkages in ${\mathrm{P}}_4{\mathrm{O}}_{10}$ and ${\mathrm{P}}_4{\mathrm{O}}_6$ are respectively -

1.  6,6 

2.  6, 8

3.  8, 6

4.  8, 8

In which of the following molecule the intramolecular hydrogen bonding is not existing.

1.  chloral hydrate

2.  0-chlorophenol

3.  choral

4.  salicylic acid

Isostructural pair among the following is:

1. ${\mathrm{BCl}}_3$ $\mathrm{and}$ ${\mathrm{BrCl}}_3$

2. ${\mathrm{NH}}_3$ $\mathrm{and}$ ${\mathrm{NO}}_3^{-}$

3. ${\mathrm{NF}}_3$ $\mathrm{and}$ ${\mathrm{BF}}_3$

4. ${\mathrm{BF}}_4^{-}$ $\mathrm{and}$ ${\mathrm{NH}}_4^{+}$

The correct order of covalent bond character among
LiCl, BeCl₂, BCl₃ and CCl₄, is:

1. LiCl < BeCl₂ > BCl₃ > CCl₄

2. LiCl > BeCl₂ < BCl₃ < CCl₄

3. LiCl < BeCl₂ < BCl₃ < CCl₄

4. LiCl > BeCl₂ > BCl₃ > CCl₄