The pair that is isostructural (i.e. having the same shape and hybridization) is

1.  ${\mathrm{NH}}_3 \mathrm{and} {\mathrm{BF}}_3$

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

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

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

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

1.  ${\mathrm{NH}}_3 > {\mathrm{NF}}_3 > {\mathrm{H}}_2\mathrm{O}$

2.  ${\mathrm{NH}}_3 > {\mathrm{H}}_2\mathrm{O} >{\mathrm{NF}}_3$

3.  ${\mathrm{H}}_2\mathrm{O} > {\mathrm{NH}}_3>{\mathrm{NF}}_3$

4.  ${\mathrm{H}}_2\mathrm{O} >{\mathrm{NF}}_3> {\mathrm{NH}}_3$

Which of the following has the shortest bond length?

1.  ${\mathrm{O}}_2$

2.  ${{\mathrm{O}}_2}^{-}$

3.  ${{\mathrm{O}}_2}^{+}$

4.  ${{\mathrm{O}}_2}^{-2}$

Lattice energy for an ionic compound is calculated by using

1.  Kirchhoff's equation

2.  Markownikoff's rule

3.  Born Haber cycle

4.  Carnot cycle

Assuming that Hund's rule is violated by the diatomic molecule $B_2$, its bond order and magnetic nature will be respectively

1.  1, diamagnetic

2.  1, paramagnetic

3.  2, diamagnetic

4.  2, paramagnetic

In the Lewis structure of ozone $\left({\mathrm{O}}_3\right)$ the formal charge on the central oxygen atom is:  

1.  +1

2.  -1

3.  0

4.  -2

For ${\mathrm{SF}}_4$, the molecular geometry and hybridization of the central atom respectively are

1. Square planar, $ds{p}^2$

2. Tetrahedral, $s{p}^3$

3. See-saw, $s{p}^{3}d$

4. Square pyramid, $s{p}^{3}d$

Among the following species, the H–X–H angle (X=B,N or P) follows the order

1. $P{H}_3<N{H}_3<N{H}_4^{+}<B{F}_3$

2. $N{H}_3<P{H}_3<N{H}_4^{+}<B{F}_3$

3. $B{F}_3<P{H}_3<N{H}_4^{+}<N{H}_3$

4. $B{F}_3<N{H}_4^{+}<N{H}_3<P{H}_3$

What is the correct order of the σ/π bond ratio for the following compound?
A: Tetracyanomethane

B: Carbon dioxide

C: Benzene

D: 1,3-Buta-diene

1. A = B < C < D           

2. A = B < D < C           

3. A = B = C = D           

4.  C < D < A < B

From the given structures, the correct structure(s) of ${\mathrm{PF}}_3{\mathrm{Cl}}_2$ is are

l.  

ll.  

lll.  

1.  Only l

2.  Only ll

3.  Only lll

4.  l, ll and lll