${\mathrm{N}}_2$ and ${\mathrm{O}}_2$ are converted to monocations ${\mathrm{N}}_2^{+}$ and ${\mathrm{O}}_2^{+}$ respectively. Which of the following is incorrect?

1. In ${\mathrm{N}}_2^{+}$, the $\mathrm{N}-\mathrm{N}$ bond weakens.

2. In ${\mathrm{O}}_2^{+}$, the $\mathrm{O}-\mathrm{O}$ bond order increases.

3. In ${\mathrm{O}}_2^{+}$, the paramagnetism decreases.

4. ${\mathrm{N}}_2^{+}$ becomes diamagnetic.

The species, having bond angles of 120° is : 

1. PH₃ 

2. ClF₃

3. NCl₃

4. BCl₃

Which of the following pairs of compounds is isoelectronic and isostructural?
(1) BeCl_2, XeF₂
(2) Tel_2, XeF₂
(3) ${\mathrm{IBr}}_2^{-}$_, XeF₂
(4) IF₃, XeF₂

Which one of the following pairs of species have the same bond order?

(1) CO, NO

(2) O_2-  , CN-

(3) CN- , NO+

(4) N+ , CN+

In which of the following compounds is an intramolecular hydrogen bond present?

The hybridisations of atomic orbitals of nitrogen in ${\mathrm{NO}}_2^{+},<mspace\; width="1em"></mspace>{\mathrm{NO}}_3^{-}$ and ${\mathrm{NH}}_4^{+}$ are

(a) sp, sp³ and sp²               (b) sp², sp³ and sp

(c) sp, sp² and sp³               (d) sp², sp and sp³

The correct shape and hybridisation for XeF₄ are

(1) octahedral, sp³d²

(2) trigonal bipyramidal, sp³d²

(3) planar triangle, sp³d³

(4) square planar, sp³d²

In which of the following molecules, all atoms are coplanar ?

Predict the correct order among the following.

(1) lone pair-lone pair>bond pair-bond pair>lone pair-bond pair

(2) bond pair-bond pair>lone pair-bond pair>lone pair-lone pair

(3) lone pair-bond pair>bond pair-bond pair>lone pair-lone pair

(4) lone pair-lone pair>lone pair-bond pair>bond pair-bond pair

The pair of electrons in the given carbanion, CH₃C≡C^-, is present in which of the following orbitals?