The p -Block Elements

White precipitate of AgCl dissolves in aqueous ammonia solution due to formation of

PCl₅ is well known, but NCl₅ is not. Because

(a) Nitrogen is less reactive than phosphorous            

(b) Nitrogen doesn't have d-orbitals in its valence shell.

(c) catenation tendency is weaker in nitrogen than phosphorous

 (d) size of phosphorous is larger than nitrogen

Which one of the following elemental forms is not present in the enamel of the teeth?

The most stable trihalide of nitrogen is

Identify the correct statement from B₂H₆ from those given below :             

(A)  In B₂H₆, all B-H bonds are equivalent

(B)  In B₂H₆, there are four 3-centre 2- electron bonds

(C)  B₂H₆ is a Lewis acid

(D)  B₂H₆ can be synthesized from both BF₃ and NaBH₄.

(E)  B₂H₆ is planar molecule.

Choose the most appropriate answer from the options given below :

Given below are the oxides :                                                                                                                        

Na₂O, As₂O₃, N₂O, NO and Cl₂O₇

Number of amphoteric oxides is :

11.4 The state of hybridisation of B in BH₄ is

(a) sp (b) sp² (c)sp³ (d) None

11.3. Assertion: PbI₄ does not exist.

Reason: Pb—I bond initially formedduring the reaction does not release enoughenergy to unpair6s² electrons and excite oneof them to higher orbital to have four unpairedelectrons around lead atom.

11.2. Assertion: The compounds formed by highlyreactive non-metals with highly reactive metalsaregenerally ionic while compounds formed between non-metals themselves are largely covalent in character.

Reason: There are large differencesin the electronegativities of highly reactive non-metals and highly reactive metals whereas small differences in theelectronegativities among the non-metals themselves.

11.1. Assertion: Non-metals readily form anions, in contrast to metals whichreadily form cations.

Reason: In general, non-metals have higher ionisation enthalpies and higherelectronegativities than the metals.