The structure of diborane (B₂H₆) contains

• four 2c-2e bonds and two 3c-2e bonds

• two 2c-2e bonds and four 3c-2e bonds

• two 2c-2e bonds and two 3c-3e bonds

• two 2c-2e bonds and two 3c-3e bonds

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

• H₂S < SiH₄ < NH₃ < BF₃

• H₂S < NH₃ < BF₃ < SiH₄

• NH₃ < H₂S < SiH₄ < BF₃

• NH₃ < H₂S < SiH₄ < BF₃

Which one the following sets of ions represents the collection of isoelectronic species?

• K⁺ , Ca²⁺, Sc³⁺, Cl^-

• Na⁺ , Mg²⁺, Al³⁺, Cl^-

• K⁺ , Cl^- , Mg²⁺, Sc³⁺

• K⁺ , Cl^- , Mg²⁺, Sc³⁺

Among Al₂O₃, SiO₂, P₂O₃ and SO₂ the correct order of acid strength is

• SO₂ < P₂O₃ < SiO₂ < Al₂O₃

• Al₂O₃ < SiO₂ < P₂O₃ < SO₂

• Al₂O₃ < SiO₂ < SO₂ < P₂O₃

• Al₂O₃ < SiO₂ < SO₂ < P₂O₃

295.

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?

• Bond length in NO⁺ is greater than in NO

• Bond length is unpredictable

• Bond length in NO⁺ in equal to that in NO

• Bond length in NO⁺ in equal to that in NO

The states of hybridization of boron and oxygen atoms in boric acid (H₃BO₃) are respectively

• sp² and sp²

• sp³ and sp³

• sp³ and sp²

• sp³ and sp²

Which one of the following has the regular tetrahedral structure?

• XeF₄

• [Ni(CN)₄]^2-

• BF₄^-

• BF₄^-

Of the following outer electronic configurations of atoms, the highest oxidation state is achieved by which one of them?

• (n -1)d⁸ ns²

• (n-1)d⁵ ns²

• (n-1)d³ ns²

• (n-1)d³ ns²

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

• dsp³ hybridization

• sp³d² hybridization

• dsp² hybridization

• dsp² hybridization

According to molecular orbital theory, which of the following will not be a viable molecule?

• $H_2^{2-}$

• $H{e}_2^{2+}$

• $H{e}_2^{+}$

• $H_2^{-}$