In which of the following pairs the two species are not isostructural?

(1) $PC{l}_4^{+} and SiC{l}_4$

(2) $P{F}_5 and Br{F}_5$

(3) $Al{F}_6^{3-}$ and $S{F}_6$

(4) $C{O}_3^{2-} and N{O}_3^{-}$

In allene $\left(C_3{H}_4\right),$ the type(s) of hybridization of the carbon atoms is (are):

1. sp and sp³

2.  sp and sp²

3. only sp²

4.  sp² and sp³

The shape of $Xe{O}_2{F}_2$ molecule is:

(1) trigonal bipyramidal

(2) square planar

(3) tetrahedral 

(4) see-saw

How many number of water molecule (s) directly bonded to the metal centre in $CuS{O}_4 . 5H_{2}O$is

(1) 3

(2) 2

(3) 4

(4) 5

A molecule having the smallest bond angle among the following is :

The pair of species having identical shapes for molecules of both species is

1. CF${}_4$ SF${}_4$

2. XeF${}_2$ CO${}_2$

3. BF${}_3$ PCI${}_3$

4. PF${}_5$IF${}_5$

The correct order of bond angles (smallest first) in H₂S, NH₃, BF₃ and SiH₄ is 

1. H₂S < SiH₄ < NH₃  < BF₃

2. NH₃ < H₂S < SiH₄ < BF₃

3. H₂S < NH₃ < SiH₄ < BF₃

4. H₂S < NH₃ < BF₃ < SiH₄

The bond order in NO is 2.5 while that in NO${}^{+}$ is 3.

Which of the following statements is true for these

two species? 

1. bond length in NO${}^{+}$ is greater than in NO

2. bond length in NO is greater than in NO${}^{+}$

3. bond length in NO${}^{+}$ is equal than in NO

4. bond length is unpredictable

Which of the following has the regular tetrahedral structure

1. [Ni(CN${}_4$)]${}^{2-}$

2. SF${}_4$

3. ${{\mathrm{BF}}_4}^{-}$

4. XeF${}_4$

The maximum number of 90$°$ angles between bond pair-bond pair of electrons is observed in : 

1. ${\mathrm{sp}}^3{\mathrm{d}}^2$ hybridization.

2. ${\mathrm{sp}}^3\mathrm{d}$ hybridization.

3. ${\mathrm{sp}}^3$ hybridization.

4. ${\mathrm{dsp}}^2$ hybridization.