Which of the following does not have a lone pair on the central atom ?

• NH₃

• PH₃

• BF₃

• PCl₃

192.

What is the nature of the bond between B and O in (C₂H₅)₂OBH₃ ?

• Covalent

• Co - ordinate covalent

• Ionic bond

• Banana shaped bond

Among the following molecules

(i) $\stackrel{..}{\mathrm{X}}$eO₃ (ii) $\stackrel{..}{\mathrm{X}}$eOF₄ (iii) $\stackrel{..}{\mathrm{X}}$eF₆ 

those having same number of lone pairs on Xe are

• (i) and (ii) only

• (i) and (iii) only

• (ii) and (iii) only

• (i), (ii) and (iii)

The diamagnetic species is

• [Ni(CN)₄]^2-

• [NiCl₄]^2-

• [CoCl₄]^2-

• [CoF₆]^2-

In diborane, the two H - B - H angles are nearly

• 60°, 120°

• 95°, 120°

• 95°, 150°

• 120°, 180°

The bond order of O₂⁺ is the same as in :

• N₂⁺

• CN^-

• CO

• NO⁺

What type of hybridisation takes place in the N atom of NH₃ ?

• sp²

• sp³

• dsp²

• sp

Assertion : Molecular nitrogen is less reactive than molecular oxygen.

Reason : The bond length of N₂ is shorter than that of oxygen.

• If both assertion and reason are true and reason is the correct explanation of the assertion.

• If both assertion and reason are true but reason is not the correct explanation of the assertion.

• If assertion is true, but reason is false.

• Both assertion and reason are false statements.

Assertion : Potassium ferrocyanide is diamagnetic whereas potassium ferricyanide is paramagnetic.

Reason : Crystal field splitting in ferrocyanide ion is greater than that of ferricyanide ion.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : SeCl₄ does not have a tetrahedral structure.

Reason : Se in SeCl₄ has two lone pairs.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.